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Microwave assistance of labeling hippuric acid by I-131.
Sherlock Huang, Lin-Chiang; Wu, Kou-Hung; Ko, Pi-Wen; Hsieh, Cheng-Ying; Pao, Kuan-Chuan; Chou, Shih-Ching; Shieh, Fa-Kuen; Sureshbabu, Radhakrishnan; Hsu, Ming-Hua
This work presents a novel approach for labeling hippuric acid with I-131 using microwaves. It utilizes copper(II) acetate as a catalyst of the labeling. The process involves the use of this catalytic copper(II) acetate at low dilutions that were nevertheless sufficient to produce labeled hippuric acid with high radiochemical purity in a short time. Therefore, the novel technique overcomes the limitations of previously reported conventional methods that involve heating. PMID:24589448
Measurement of urinary hippuric and m-methylhippuric acids by gas chromatography
Buchet, J. P.; Lauwerys, R. R.
Buchet, J. P., and Lauwerys, R. R. (1973).British Journal of Industrial Medicine,30, 125-128. Measurement of urinary hippuric and m-methylhippuric acids by gas chromatography. A gas chromatographic method for the determination of hippuric and m-methylhippuric acids in urine is described. A known amount of heptadecanoic acid (internal standard) is added to the urine before its extraction with ethyl acetate. After evaporation of the solvent, the acids are methylated with diazomethane. The residue is taken up in methanol and injected into the gas chromatograph. The ratio of the height of the hippuric or m-methylhippuric acid peak to the height of the heptadecanoic acid peak is calculated and by reference to a calibration curve prepared in the same conditions the urine concentration of the two acids is determined. PMID:4703083
Thiourea derivatives incorporating a hippuric acid moiety: synthesis and evaluation of antibacterial and antifungal activities.
Abbas, Samir Y; El-Sharief, Marwa A M Sh; Basyouni, Wahid M; Fakhr, Issa M I; El-Gammal, Eman W
New series of thiourea derivatives incorporating a hippuric acid moiety have been synthesized through the reaction of 4-hippuric acid isothiocyanate with various nitrogen nucleophiles such as aliphatic amines, aromatic amines, sulfa drugs, aminopyrazoles, phenylhydrazine and hydrazides. The synthesized compounds were tested against bacterial and fungal strains. Most of compounds, such as 2-(4-(3-(3-bromophenyl)thioureido)benzamido)acetic acid and 2-(4-(3-(4-(N-pyrimidin-2-ylsulfamoyl)phenyl)thioureido)benzamido)acetic acid, showed significant antibacterial and antifungal activities. These compounds comprise a new class of promising broad-spectrum antibacterial and antifungal agents. PMID:23644194
Hippuric acid in 24 h urine collections as a biomarker of fruits and vegetables intake in kidney stone formers.
Guerra, Angela; Folesani, Giuseppina; Mena, Pedro; Ticinesi, Andrea; Allegri, Franca; Nouvenne, Antonio; Pinelli, Silvana; Del Rio, Daniele; Borghi, Loris; Meschi, Tiziana
This work aimed to underline the prospects of hippuric acid, a product of the metabolism of polyphenols, as a new biomarker of fruits and vegetables intake associated with lithogenic risk. Biochemical parameters of lithogenic risk and hippuric acid were measured in the 24 h urine collections of a cohort of 696 Italian kidney stone formers divided into two subgroups according to their different dietary habits. The link between lithogenic risk parameters and hippuric acid was assessed and this compound was revealed as a valuable biomarker of fruits and vegetables intake in kidney stone formers. A cut-off value of urinary excretion of hippuric acid, 300?mg/24?h, was set as the threshold of discrimination between low and high intake of fruits and vegetables for these patients. These results highlight the importance of monitoring of the excretion hippuric acid in urine to address proper dietary guidelines for the management of stone former patients. PMID:25198158
Hippuric acid, phenol, and trichloroacetic acid levels in the urine of Japanese subjects with no known exposure to organic solvents
Ikeda, Masayuki; Ohtsuji, Hatsue
Ikeda, M., and Ohtsuji, H. (1969).Brit. J. industr. Med.,26, 162-164. Hippuric acid, phenol, and trichloroacetic acid levels in the urine of Japanese subjects with no known exposure to organic solvents. Urine samples from 36 male and 30 female university students and 31 male factory workers with no known exposure to industrial organic solvents were analysed for hippuric acid, phenol, and trichloroacetic acid, which are the major metabolites of toluene, benzene, and trichloroethylene respectively. The normal levels were less than 1·4 g./l. for hippuric acid, less than 80 mg./l. for phenol, and less than 1 mg./l. for trichloroacetic acid. No evidence was obtained to suggest that correction for urine concentration with either specific gravity or creatinine concentration minimizes individual variation of metabolite levels. PMID:5780109
Synthesis of thiosemicarbazones derived from N-(4-hippuric acid)thiosemicarbazide and different carbonyl compounds as antimicrobial agents.
El-Sharief, Marwa A M Sh; Abbas, Samir Y; El-Bayouki, Khairy A M; El-Gammal, Eman W
New series of thiosemicarbazone derivatives incorporating a hippuric acid moiety have been synthesized through the reaction of N-(4-hippuric acid)thiosemicarbazide with various carbonyl compounds such as aldehydes, ketones and cyclic ketones. The synthesized compounds were tested against bacterial and fungal strains. Most of compounds, such as 2-(4-(2-(4-fluorobenzylidene)hydrazinecarbothioamido)benzamido)acetic acid showed significant antibacterial and antifungal activities. These compounds comprise a new class of promising broad-spectrum antibacterial and antifungal agents. PMID:23871906
Hippuric acid as a significant regulator of supersaturation in calcium oxalate lithiasis: the physiological evidence.
Atanassova, Stoyanka S; Gutzow, Ivan S
At present, the clinical significance of existing physicochemical and biological evidence and especially the results we have obtained from our previous in vitro experiments have been analyzed, and we have come to the conclusion that hippuric acid (C6H5CONHCH2COOH) is a very active solvent of Calcium Oxalate (CaOX) in physiological solutions. Two types of experiments have been discussed: clinical laboratory analysis on the urine excretion of hippuric acid (HA) in patients with CaOX lithiasis and detailed measurements of the kinetics of the dissolution of CaOX calculi in artificial urine, containing various concentrations of HA. It turns out that the most probable value of the HA concentration in the control group is approximately ten times higher than the corresponding value in the group of the stone-formers. Our in vitro analytical measurements demonstrate even a possibility to dissolve CaOX stones in human urine, in which increased concentration of HA have been established. A conclusion can be that drowning out HA is a significant regulator of CaOX supersaturation and thus a regulation of CaOX stone formation in human urine. Discussions have arisen to use increased concentration of HA in urine both as a solubilizator of CaOX stones in the urinary tract and on the purpose of a prolonged metaphylactic treatment. PMID:24307993
Assessment of the capabilities of capillary zone electrophoresis for the determination of hippuric and orotic acid in whey.
Tienstra, P A; van Riel, J A; Mingorance, M D; Olieman, C
A rapid method was developed for the simultaneous determination of hippuric and orotic acid in rennet whey by capillary zone electrophoresis using an uncoated capillary utilizing a 0.04 M amino-2-methyl-1,3-propanediol (AMPD)-N,N-bis(2-hydroxyethyl) glycine (BICINE) buffer (pH 8.8) with UV detection at 254 and 280 nm. Whey proteins were removed by ultrafiltration. The method was evaluated for external, internal and standard addition procedures for both peak areas and peak heights. The use of an internal standard (sorbic acid) eliminated injection errors and gave, when applied to peak areas, the same levels for hippuric and orotic acid in those obtained with high-performance liquid chromatography. Relative standard deviations were 1-2%. Peak heights gave erratic results owing to sample matrix effects on peak widths. PMID:1430035
The vapour pressures over saturated aqueous solutions of dl-2-aminobutyric acid, 4-aminobutyric acid, sodium- d-gluconate, sodium hippurate, and potassium magnesium- l-aspartate
Alexander Apelblat; Eli Korin
Vapour pressures of water over saturated solutions of dl-2-aminobutyric acid, 4-aminobutyric acid, sodium-d-gluconate, sodium hippurate, and potassium magnesium-l-aspartate were determined over the (278 to 322)K temperature range. The determined vapour pressures were used to obtain the water activities, the molar enthalpies of vaporization, and the osmotic coefficients of sodium-d-gluconate.
Evaluation of hippuric acid content in goat milk as a marker of feeding regimen.
Carpio, A; Bonilla-Valverde, D; Arce, C; Rodríguez-Estévez, V; Sánchez-Rodríguez, M; Arce, L; Valcárcel, M
Organic producers, traders, and consumers must address 2 issues related to milk: authentication of the production system and nutritional differentiation. The presence of hippuric acid (HA) in goat milk samples has been proposed as a possible marker to differentiate the feeding regimen of goats. The objective of this work is to check the hypothesis that HA could be a marker for the type of feeding regimen of goats by studying the influence of production system (conventional or organic) and feeding regimen (with or without grazing fodder). With this purpose, commercial cow and goat milk samples (n=27) and raw goat milk samples (n=185; collected from different breeds, localizations, and dates) were analyzed. Samples were grouped according to breed, feeding regimen, production system, and origin to compare HA content by ANOVA and honestly significant difference Tukey test at a confidence level of ?95%. Hippuric acid content was obtained by analyzing milk samples with capillary electrophoresis. This method was validated by analyzing part of the samples with HPLC as a reference technique. Sixty-nine raw goat milk samples (of the total 158 samples analyzed in this work) were quantified by capillary electrophoresis. In these samples, the lowest average content for HA was 7±3 mg/L. This value corresponds to a group of conventional raw milk samples from goats fed with compound feed. The highest value of this group was 28±10 mg/L, corresponding to goats fed compound feed plus grass. Conversely, for organic raw goat milk samples, the highest concentration was 67±14 mg/L, which corresponds to goats fed grass. By contrast, the lowest value of this organic group was 26±10 mg/L, which belongs to goats fed organic compounds. Notice that the highest HA average content was found in samples from grazing animals corresponding to the organic group. This result suggests that HA is a good marker to determine the type of goats feeding regimen; a high content of HA represents a diet based mainly or exclusively on eating green grass (grazing), independently of the production system. Hence, this marker would not be useful for the actual organic policies to distinguish organic milk under the current regulations, because organic dairy ruminants can be fed organic compound feed and conserved fodder without grazing at all. PMID:23849634
Heterogeneous Electrochemical Immunoassay of Hippuric Acid on the Electrodeposited Organic Films
Choi, Young-Bong; Kim, Nam-Hyuk; Kim, Seung-Hoi; Tae, Gun-Sik; Kim, Hyug-Han
By directly coordinating hippuric acid (HA) to the ferrate (Fe) as an electron transfer mediator, we synthesized a Fe-HA complex, which shows a good electrochemical signal and thus enables the electrochemical immunoanalysis for HA. We electrodeposited organic films containing imidazole groups on the electrode surface and then bonded Ni ion (positive charge) to induce immobilization of Fe-HA (negative charge) through the electrostatic interaction. The heterogeneous competitive immunoassay system relies on the interaction between immobilized Fe-HA antigen conjugate and free HA antigen to its antibody (anti-HA). The electric signal becomes weaker due to the hindered electron transfer reaction when a large-sized HA antibody is bound onto the Fe-HA. However, in the presence of HA, the electric signal increases because free HA competitively reacts with the HA antibody prior to actual reaction and thus prevents the HA antibody from interacting with Fe-HA at the electrode surface. This competition reaction enabled an electrochemical quantitative analysis of HA concentration with a detection limit of 0.5 ?g mL?1, and thus allowed us to develop a simple and rapid electrochemical immunosensor. PMID:25313491
Homogeneous electrochemical detection of hippuric acid in urine based on the osmium-antigen conjugate.
Jeon, Won-Yong; Choi, Young-Bong; Kim, Hyug-Han
A homogeneous electrochemical immunoassay is based on the interaction of osmium-antigen conjugate with its antibody. The novelty presented herein is the direct conjugation of the osmium complex to a small antigen and the application of the quantitative analysis of the antigen and its antibody as the electrical signal for homogeneous immunoassay. The small antigen chosen is hippuric acid (HA), a major urinary metabolite in toluene-exposed humans. As a redox mediator, [Os(4,4'-dimethoxy-2,2'-bipyridine)2(4-aminomethylpyridine-HA)Cl](+/2+) (Os-HA antigen) has been synthesized and characterized on screen-printed carbon electrodes. The synthesized Os-HA antigen shows reversible redox peaks at E(˝)=0.056 V versus Ag/AgCl. The homogeneous competitive immunoassay relies on the interaction between Os-HA antigen conjugate and free antigen to its antibody, which can generate electrical signals linearly proportional to the free antigen monitored by cyclic voltammetry and differential pulse voltammetry in the range of 10 ?g mL(-1) to 5.12 mg mL(-1). The cutoff concentration of HA in urine samples is 2.0 mg mL(-1), so the method can be used to develop a HA immunosensor. Moreover, the proposed homogeneous electrochemical immunoassay method can be applied to detect low concentrations of small antigens found in the healthcare area. PMID:23589467
Heterogeneous electrochemical immunoassay of hippuric acid on the electrodeposited organic films.
Choi, Young-Bong; Kim, Nam-Hyuk; Kim, Seung-Hoi; Tae, Gun-Sik; Kim, Hyug-Han
By directly coordinating hippuric acid (HA) to the ferrate (Fe) as an electron transfer mediator, we synthesized a Fe-HA complex, which shows a good electrochemical signal and thus enables the electrochemical immunoanalysis for HA. We electrodeposited organic films containing imidazole groups on the electrode surface and then bonded Ni ion (positive charge) to induce immobilization of Fe-HA (negative charge) through the electrostatic interaction. The heterogeneous competitive immunoassay system relies on the interaction between immobilized Fe-HA antigen conjugate and free HA antigen to its antibody (anti-HA). The electric signal becomes weaker due to the hindered electron transfer reaction when a large-sized HA antibody is bound onto the Fe-HA. However, in the presence of HA, the electric signal increases because free HA competitively reacts with the HA antibody prior to actual reaction and thus prevents the HA antibody from interacting with Fe-HA at the electrode surface. This competition reaction enabled an electrochemical quantitative analysis of HA concentration with a detection limit of 0.5 ?g mL(-1), and thus allowed us to develop a simple and rapid electrochemical immunosensor. PMID:25313491
In situ N2O emissions are not mitigated by hippuric and benzoic acids under denitrifying conditions.
Krol, D J; Forrestal, P J; Lanigan, G J; Richards, K G
Ruminant urine patches deposited onto pasture are a significant source of greenhouse gas nitrous oxide (N2O) from livestock agriculture. Increasing food demand is predicted to lead to a rise in ruminant numbers globally, which, in turn will result in elevated levels of urine-derived N2O. Therefore mitigation strategies are urgently needed. Urine contains hippuric acid and together with one of its breakdown products, benzoic acid, has previously been linked to mitigating N2O emissions from urine patches in laboratory studies. However, the sole field study to date found no effect of hippuric and benzoic acid concentration on N2O emissions. Therefore the aim of this study was to investigate the in situ effect of these urine constituents on N2O emissions under conditions conducive to denitrification losses. Unadulterated bovine urine (0 mM of hippuric acid, U) was applied, as well as urine amended with either benzoic acid (96 mM, U+BA) or varying rates of hippuric acid (8 and 82 mM, U+HA1, U+HA2). Soil inorganic nitrogen (N) and N2O fluxes were monitored over a 66 day period. Urine application resulted in elevated N2O flux for 44 days. The largest N2O fluxes accounting for between 13% (U) and 26% (U+HA1) of total loss were observed on the day of urine application. Between 0.9 and 1.3% of urine-N was lost as N2O. Cumulative N2O loss from the control was 0.3 kg N2O-Nha(-1) compared with 11, 9, 12, and 10 kg N2O-Nha(-1) for the U, U+HA1, U+HA2, and U+BA treatments, respectively. Incremental increases in urine HA or increase in BA concentrations had no effect on N2O emissions. Although simulation of dietary manipulation to reduce N2O emissions through altering individual urine constituents appears to have no effect, there may be other manipulations such as reducing N content or inclusion of synthetic inhibitory products that warrant further investigation. PMID:25553550
Structural, spectroscopic, and nonlinear optical investigations on a novel nonlinear optical crystal: hippuric acid doped ammonium di hydrogen phosphate (HAADP).
Kumaresh, A; Kumar, R Arun
Transparent single crystals of pure and 1 mol% hippuric acid doped ammonium di hydrogen phosphate (HAADP) were grown from aqueous solution by employing slow evaporation technique. Crystallinity of the grown crystals was studied by powder X-ray diffraction analysis. Both pure ADP and HAADP crystals exhibit tetragonal crystal structure. The bonding structure and molecular associations due to chemical reactions were analyzed by FTIR spectroscopy. It also confirms the functional groups present in the grown crystals. UV-Vis-NIR spectral analysis was carried out to study the optical characteristics of the crystals which reveal that the cutoff wavelength for both pure and hippuric acid doped ADP crystal is around 300 nm. From these spectra it can be clearly inferred that there is an absence of characteristic absorption in the region between 340 and 1200 nm, which is a most desirable property of a material for both SHG and other NLO applications. Second harmonic generation (SHG) test adopting the Kurtz Perry technique revealed that the second harmonic generation efficiency of HAADP is 1.5 times that of pure ADP crystal. PMID:24287047
Growth, structural and optical characterization of a new nonlinear optical crystal--hippuric acid doped potassium di hydrogen phosphate.
Kumaresh, A; Arun Kumar, R
Potassium di hydrogen phosphate (KDP) is an efficient nonlinear optical crystal employed in frequency conversion applications. 1mol% hippuric acid doped potassium di hydrogen phosphate (HAKDP) crystals with the dimensions 35×8×4 mm(3) were grown using the slow evaporation technique. The grown HAKDP crystal is iso-structural with pure KDP, but a variation in the crystallographic parameters was observed. The UV-VIS-NIR study suggests that the crystal is highly transparent in the region 340-1200 nm. The functional groups present in the grown crystal were observed in the FTIR analysis. The powder SHG test performed on the grown crystal revealed the NLO efficiency of the crystal has increased due to doping when compared with pure KDP crystal. PMID:23648967
A detailed perceptive on the growth and characterization studies of para amino hippuric acid (PAHA) single crystals.
Sathesh Kumar, K; Srinivasan, P; Mahadevan Pillai, V P
Single crystals of para amino hippuric acid (PAHA) were grown by slow evaporation technique. The spectral and its structural properties of the crystals were studied by FT-IR, micro-Raman and factor group analysis. The optical transparency in the UV-Visible regions was found to be good for non-linear optics (NLO) applications. Thermogravimetric analysis (TGA) and Differential Thermal Analysis (DTA) showed that the compound decomposes beyond 300°C. The dielectric behavior of the compound predicts low dielectric loss at high frequency applied whereas in the case of mechanical behavior of the specimen hardness increases with increasing applied load. After certain weight increase, hardness gets saturated in the region of ?110. Relative second harmonic efficiency of the compound is found to be 1.8 times greater than that of potassium di-phosphate reference. PMID:24873892
A detailed perceptive on the growth and characterization studies of para amino hippuric acid (PAHA) single crystals
NASA Astrophysics Data System (ADS)
Sathesh Kumar, K.; Srinivasan, P.; Mahadevan Pillai, V. P.
Single crystals of para amino hippuric acid (PAHA) were grown by slow evaporation technique. The spectral and its structural properties of the crystals were studied by FT-IR, micro-Raman and factor group analysis. The optical transparency in the UV-Visible regions was found to be good for non-linear optics (NLO) applications. Thermogravimetric analysis (TGA) and Differential Thermal Analysis (DTA) showed that the compound decomposes beyond 300 °C. The dielectric behavior of the compound predicts low dielectric loss at high frequency applied whereas in the case of mechanical behavior of the specimen hardness increases with increasing applied load. After certain weight increase, hardness gets saturated in the region of ?110. Relative second harmonic efficiency of the compound is found to be 1.8 times greater than that of potassium di-phosphate reference.
Determination of o-cresol by gas chromatography and comparison with hippuric acid levels in urine samples of individuals exposed to toluene
Amorim, L.C.A.; Alvarez-Leite, E.M. [Federal Univ. of Minas Gerais (Brazil)
Hippuric acid is the most frequently used biomarker in the biological monitoring of occupational exposure to toluene. This product of solvent biotransformation may be also found in the urine of individual who have not been exposed to the solvent. A smaller fraction of the absorbed toluene is oxidized to aromatic compounds including ortho-cresol, which is not found significantly in the urine of nonexposed individuals. An analytical methodology whereby gas chromatography with flame ionization detection is utilized for determination of o-cresol in urine of workers exposed to toluene is described. The levels obtained were subsequently compared to hippuric acid levels determined in the same urine samples. The analytical method has demonstrated an adequate precision (intra- and interassay coefficient of variation in the range of 2.4-5.4%) and average recovery of 98%. The samples for o-cresol determination were obtained from workers exposed to toluene in three different industrial activities. The concentration range found in exposed groups varied from {le}0.21 to 2.8 {mu}g/ml. The o-cresol values in the urine did not differ significantly among the exposed groups analyzed at the 5% level. The o-cresol and hippuric acid values found in the urine samples showed a significant correlation at the 1% level. These results may represent an additional contribution to studies for a definitive evaluation of the validity of o-cresol as a biomarker of exposure to toluene. 16 refs., 3 tabs.
Biomarkers of toluene exposure in rats: mercapturic acids versus traditional indicators (urinary hippuric acid and o-cresol and blood toluene).
Cosnier, Frédéric; Cossec, Benoît; Burgart, Manuella; Nunge, Hervé; Brochard, Céline; Décret, Marie-Josčphe; Rémy, Aurélie
1. Toluene (TOL) is a neurotoxic, ototoxic and reprotoxic solvent which is metabolized via the glutathione pathway, producing benzylmercapturic, o-, m- and p-toluylmercapturic acids (MAs). These metabolites could be useful as biomarkers of TOL exposure. 2. The aims of this study were (1) to provide data on MAs excretion in rat urine following TOL exposure by inhalation, (2) to compare them to data from traditional TOL biomarkers, i.e. TOL in blood (Tol-B), and urinary hippuric acid (HA) and o-cresol (oCre) and (3) to establish a relationship between these different indicators and the airborne TOL concentration (Tol-A). 3. Sprague-Dawley rats were exposed to a range of TOL concentrations. Blood and urine were collected and analyzed to determine biomarker levels. 4. Levels of the four MAs correlate strongly with Tol-A (comparable to the correlation with Tol-B). 5. MAs are thus clearly superior to oCre and HA as potential markers of exposure to TOL. PMID:23278281
Gas-liquid chromatography technique for detection of hippurate hydrolysis and conversion of fumarate to succinate by microorganisms.
Kodaka, H; Lombard, G L; Dowell, V R
A gas-liquid chromatography technique which allows simultaneous detection of hippuric acid (N-benzoylglycine) hydrolysis and conversion of fumaric acid to succinic acid by microorganisms uses a new medium, hippurate-formate-fumarate broth, and a gas chromatograph equipped with a thermal conductivity detector. This technique gave more reproducible results than other tests used in the study for detecting hippurate hydrolysis and also gave consistent results in detecting succinic acid produced from utilization of fumaric acid. PMID:7153346
On-line detection of hippuric acid by microextraction with a molecularly-imprinted polysulfone membrane sorbent and liquid chromatography-tandem mass spectrometry.
Moein, Mohammad Mahdi; El-Beqqali, Aziza; Javanbakht, Mehran; Karimi, Mohammad; Akbari-Adergani, Behrouz; Abdel-Rehim, Mohamed
Destruction of sorbents during consecutive extractions using the micro-extraction by packed sorbent (MEPS) technique is a serious problem. In MEPS the complex matrix such as plasma and blood can affect the sorbent physical properties and the sorbent can be deteriorated after handling of few samples. To overcome this problem, the surface of a polysulfone membrane (PSM) was modified by a molecularly imprinted sol-gel and utilized for online extraction of a lung cancer biomarker, hippuric acid (HA), in biological matrices. The molecularly imprinted polymer membrane provided fast, sensitive, selective and robust sample preparation method for HA in biological fluids. In addition, MIP membrane could be used for up to 50 extractions without a significant change in extraction recovery. To achieve the best results, the parameters that influenced the extraction efficiency were thoroughly investigated. Moreover, for evaluating the performance of the molecularly imprinted sol-gel membrane (MISM), a non-molecularly imprinted sol-gel membrane (NISM) as a blank was prepared. The limits of detection (LOD) and quantification (LOQ) for HA in both plasma and urine samples were 0.30nmolL(-1) and 1.0nmolL(-1), respectively. Standard calibration curves were obtained over the range of 1-1000nmolL(-1) for HA in plasma and urine samples. The coefficients of determination (R(2)) were ?0.997. The extraction recoveries of HA from human plasma and urine samples were higher than 91%. The precision values for HA in plasma and urine samples were 2.2-4.8% and 1.1-6.7%, respectively. PMID:25468498
Preparation of hippurate-zinc layered hydroxide nanohybrid and its synergistic effect with tamoxifen on HepG2 cell lines
Ali, Samer Hasan Hussein Al; Al-Qubaisi, Mothanna; Hussein, Mohd Zobir; Zainal, Zulkarnain; Hakim, Muhammad Nazrul
Background A new simple preparation method for a hippurate-intercalated zinc-layered hydroxide (ZLH) nanohybrid has been established, which does not need an anion-exchange procedure to intercalate the hippurate anion into ZLH interlayers. Methods The hippuric acid nanohybrid (HAN) was prepared by direct reaction of an aqueous suspension of zinc oxide with a solution of hippuric acid via a one-step method. Results The basal spacing of the nanohybrid was 21.3 Ĺ, indicating that the hippurate anion was successfully intercalated into the interlayer space of ZLH, and arranged in a monolayer fashion with the carboxylate group pointing toward the ZLH inorganic interlayers. A Fourier transform infrared study confirmed the formation of the nanohybrid, while thermogravimetry and differential thermogravimetry analyses showed that the thermal stability of the nanohybrid was markedly enhanced. The loading of hippurate in the nanohybrid was estimated to be about 38.7% (w/w), and the release of hippurate from the nanohybrid was of a controlled manner, and therefore the resulting material was suitable for use as a controlled-release formulation. HAN has synergistic properties with tamoxifen toward a HepG2 cell line, with an IC50 value of 0.35 compared with hippurate. In the antiproliferative assay, the ratio of viable cells account for cells treated by the combination tamoxifen with HAN to untreated cells was sharply reduced from 66% to 13% after 24 and 72 hours, respectively. Conclusion The release of hippuric acid anions from HAN occurred in a controlled manner, and the resulting material is suitable for a controlled-release formulation. PMID:22163163
Evaluation of metabolism and disposition of GDC-0152 in rats using 14C labeling strategy at two different positions: a novel formation of hippuric acid from 4-phenyl-5-amino-1,2,3-thiadiazole.
Yue, Qin; Mulder, Teresa; Rudewicz, Patrick J; Solon, Eric; Budha, Nageshwar; Ware, Joseph A; Lyssikatos, Joseph; Hop, Cornelis E C A; Wong, Harvey; Khojasteh, S Cyrus
The compound (S)-1-[(S)-2-cyclohexyl-2-([S]-2-[methylamino]propanamido)acetyl]-N-(4-phenyl-1,2,3-thiadiazol-5-yl)pyrrolidine-2-carboxamide (GDC-0152) is a peptidomimetic small molecule antagonist of inhibitor of apoptosis (IAP) proteins with antitumor activity. The mass balance, pharmacokinetics, tissue distribution and metabolism of GDC-0152 was investigated in rats following intravenous administration of 15 mg/kg of [(14)C]GDC-0152, labeled either at the terminal phenyl ring (A) or at the carbonyl of the 2-amino-2-cyclohexylacetyl moiety (B). In rats, 92.2%-95.1% of the radiolabeled GDC-0152 dose was recovered. Approximately 62.3% and 25.1% of A was excreted in urine and feces, respectively. By contrast, B was excreted almost equally in urine (27.2%), feces (32.2%), and expired air (27.5%). GDC-0152 underwent extensive metabolism, with less than 9% of the dose recovered as parent in excreta. Similarly, in plasma, GDC-0152 represented 16.7% and 7.5% of the area under the curve of the total radioactivity for A and B, respectively. The terminal half-life (t(1/2)) for total radioactivity was longer for B (21.2 hours) than for A (4.59 hours). GDC-0152 was highly metabolized via oxidation and amide hydrolysis, followed by subsequent sulfation and glucuronidation. The most abundant circulating metabolites were the amide hydrolyzed products, M26, M28, M30, M31, and M34, which ranged from 3.5% to 9.0% of total radioactivity. In quantitative whole-body autoradiography studies, the residence of radioactivity in tissues was longer for B than for A, which is consistent with the t(1/2) of the total radioactivity in circulation. A novel 4-phenyl-5-amino-1,2,3-thiadiazole (M28) oxidative cleavage resulted in the formation of hippuric acid (M24). This biotransformation was also observed in rat hepatocyte incubations with para-substituted M28 analogs. In addition, the formation of M24 was inhibited by 1-aminobenzotriazole, which points to the involvement of P450 enzymes. PMID:23223496
Differences in gut microbial metabolism are responsible for reduced hippurate synthesis in Crohn's disease
Horace RT Williams; I Jane Cox; David G Walker; Jeremy FL Cobbold; Simon D Taylor-Robinson; Sara E Marshall; Timothy R Orchard
BACKGROUND: Certain urinary metabolites are the product of gut microbial or mammalian metabolism; others, such as hippurate, are mammalian-microbial 'co-metabolites'. It has previously been observed that Crohn's disease (CD) patients excrete significantly less hippurate than controls. There are two stages in the biosynthesis of this metabolite: 1) gut microbial metabolism of dietary aromatic compounds to benzoate, and 2) subsequent hepatorenal
Determination of Organic Acids and Volatile Flavor Substances in Kefir during Fermentation
Z. B. Güzel-Seydim; A. C. Seydim; A. K. Greene; A. B. Bodine
The production of organic acids and volatile flavor components was measured during kefir starter culture fermentation. Samples were collected at 0, 5, 10, 15, and 22 h of fermentation (final pH=4.6). Samples were analyzed for orotic, citric, pyruvic, uric, lactic, acetic, butyric, propionic and hippuric acids by HPLC. Acetaldehyde, ethanol, acetoin and diacetyl production were monitored using GC equipped with
Quantitative UPLC-MS/MS analysis of the gut microbial co-metabolites phenylacetylglutamine, 4-cresyl sulphate and hippurate in human urine: INTERMAP Study
Wijeyesekera, Anisha; Clarke, Philip A.; Bictash, Magda; Brown, Ian J.; Fidock, Mark; Ryckmans, Thomas; Yap, Ivan K. S.; Chan, Queenie; Stamler, Jeremiah; Elliott, Paul; Holmes, Elaine; Nicholson, Jeremy K.
The role of the gut microbiome in human health, and non-invasive measurement of gut dysbiosis are of increasing clinical interest. New high-throughput methods are required for the rapid measurement of gut microbial metabolites and to establish reference ranges in human populations. We used ultra-performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS) -- positive and negative electrospray ionization modes, multiple reaction monitoring transitions -- to simultaneously measure three urinary metabolites (phenylacetylglutamine, 4-cresyl sulphate and hippurate) that are potential biomarkers of gut function, among multi-ethnic US men and women aged 40–59 from the INTERMAP epidemiologic study (n = 2000, two timed 24-hr urine collections/person). Metabolite concentrations were quantified via stable isotope labeled internal standards. The assay was linear in the ranges 1ng/mL (lower limit of quantification) to 1000ng/mL (phenylacetylglutamine and 4-cresyl sulfate) and 3ng/mL to 3000ng/mL (hippurate). These quantitative data provide new urinary reference ranges for population-based human samples: mean (standard deviation) 24-hr urinary excretion for phenylacetylglutamine was: 1283.0 (751.7) ?mol/24-hr (men), 1145.9 (635.5) ?mol/24-hr (women); for 4-cresyl sulphate, 1002.5 (737.1) ?mol/24-hr (men), 1031.8 (687.9) ?mol/24-hr (women); for hippurate, 6284.6 (4008.1) ?mol/24-hr (men), 4793.0 (3293.3) ?mol/24-hr (women). Metabolic profiling by UPLC-MS/MS in a large sample of free-living individuals has provided new data on urinary reference ranges for three urinary microbial co-metabolites, and demonstrates the applicability of this approach to epidemiological investigations. PMID:23946767
A difference in the incorporation of 14C into hippurate glycine from dl-[2-14C]glutamate and dl-[5-14C]glutamate in guinea pigs
Rowsell, Kathleen V.; Ali, Tahsin A. J.; Rowsell, Edward V.
The specific radioactivity of urinary hippurate glycine was determined after injecting guinea pigs with benzoate and either dl-[2-14C]glutamate or dl-[5-14C]glutamate. The isotope dilution factor for the formation of [14C]glycine was significantly greater (30%) with C-2 labelled glutamate. With either form of labelled glutamate the hippurate glycine was largely carboxyl-group labelled. The observations suggest a route for the incorporation of glutamate carbon into glycine that involves C-5 but not C-2. A hypothesis for glycine biosynthesis from l-glutamate is advanced, consistent with these findings, that includes conversion of l-glutamate to 4-hydroxy-2-oxoglutarate, the scission of the latter to glyoxylate and pyruvate, and the formation of glycine by transamination. PMID:1220690
Assessment of radiochemical design of antibodies using an ester bond as the metabolizable linkage: evaluation of maleimidoethyl 3-(tri-n-butylstannyl)hippurate as a radioiodination reagent of antibodies for diagnostic and therapeutic applications.
Arano, Y; Wakisaka, K; Ohmono, Y; Uezono, T; Akizawa, H; Nakayama, M; Sakahara, H; Tanaka, C; Konishi, J; Yokoyama, A
Reduction of radioactivity levels in nontarget tissues such as the liver and kidney constitutes a problem to be resolved in diagnostic and therapeutic applications of radiolabeled monoclonal antibodies (mAbs). A new radioiodination reagent with an ester bond to liberate m-iodohippuric acid from covalently conjugated proteins, maleimidoethyl 3-(tri-n-butylstannyl)hippurate (MIH), was recently developed. MIH liberated m-iodohippuric acid from galactosylneoglycoalbumin in murine liver, and the radiometabolite was rapidly eliminated from the liver into urine as an intact structure. In this study, intact IgG and Fab fragment of a mAb against osteogenic sarcoma were radioiodinated with MIH to further assess the applicability of MIH to radioimmunoimaging and therapy. For comparison, a mAb radioiodinated with N-succinimidyl iodobenzoate (SIB) and indium-111 (111In)-labeled mAbs with diethylenetriaminepentaacetic dianhydride (cDTPA) or 1-[4-[(5-maleimidopentyl)amino]benzyl]-ethylenediaminetetraacetic acid (EMCS-Bz-EDTA) were used. Size-exclusion HPLC analysis and cell binding assays indicated the preservation of both structure and antigen binding affinity of radioiodinated MIH-OST7 (IgG). In biodistribution studies in mice, [125I]MIH-OST7 (IgG) showed faster systemic clearance of radioactivity after 24 h postinjection than did [131I]SIB- and [111In]EMCS-Bz-EDTA-OST7 (IgG). [125I]MIH-OST7 (IgG) also exhibited much lower radioactivity levels in nontarget tissues such as the liver and kidney, with higher radioactivity levels in the blood up to 72 h postinjection when compared with [111In]cDTPA-OST7 (IgG). Radioactivity excreted from the mice was found in the urine as m-iodohippuric acid, following administration of [125I]MIH-OST7 (IgG). In athymic mice bearing osteogenic sarcoma, [131I]MIH-OST7 (IgG) indicated higher tumor-to-nontarget ratios of radioactivity at both 24 and 48 h postinjection than [125I]SIB-OST7 (IgG). Although both radioiodinated OST7s showed similar radioactivity levels in the target at 24 h postinjection, a small but significant decrease in the target radioactivity level was observed with [131I]MIH-OST7 (IgG) at 48 h postinjection. In addition, [131I]MIH-OST7 (Fab) showed very rapid cleavage of the ester bond both in vivo and in vitro. These findings indicated that while MIH may be a useful reagent for radioimmunoimaging using IgG, mAb, its application to smaller molecular weight mAbs and radioimmunotherapy would be hindered due to the labile characteristics of the ester bond in plasma. Thus, while the present study reinforced the usefulness of metabolizable linkages for reducing nontarget radioactivity levels, a development of plasma-stable metabolizable linkages is also warranted for radioimmunotherapy and for smaller molecular weight polypeptides. PMID:8950481
Urinary excretion of phenolic acids in rats fed cranberry, blueberry, or black raspberry powder.
Khanal, Ramesh; Howard, Luke R; Prior, Ronald L
Dietary polyphenolics can be converted into smaller phenolic acids (PA) by microorganisms in the colon and may contribute to health benefits associated with the parent polyphenolics. Urinary excretion of 18 PA and their conjugates was studied, using HPLC-MS/MS, in rats fed AIN93G-based diets containing 5% (dry weight basis) of either cranberry (CB), blueberry (BB), or black raspberry (BRB). Hippuric, 4-hydroxyphenylacetic, 3-methoxy-4-hydroxyphenylacetic, and 4-hydroxybenzoic acids were excreted in greatest quantity in the urine over a 24 h period in all diets. Primary PA excreted in the berry diets were 4-hydroxycinnamic acid for CB; chlorogenic, ferulic, and 3,4-dihydroxycinnamic acids for BB; and 3-hydroxyphenylpropionic, 3-hydroxybenzoic, and 3-hydroxycinnamic acids for BRB. PA were present in conjugated form with cinnamic acid derivatives being 50-70% and phenylacetic acid derivatives conjugated <10%. Conjugated, and not just the free, PA are significant contributors to total urinary excretion. PMID:24180593
Diet-derived phenolic acids regulate osteoblast and adipocyte lineage commitment and differentiation in young mice.
Chen, Jin-Ran; Lazarenko, Oxana P; Zhang, Jian; Blackburn, Michael L; Ronis, Martin J J; Badger, Thomas M
A blueberry (BB)-supplemented diet has been previously shown to significantly stimulate bone formation in rapidly growing male and female rodents. Phenolic acids (PAs) are metabolites derived from polyphenols found in fruits and vegetables as a result of the actions of gut bacteria, and they were found in the serum of rats fed BB-containing diet. We conducted in vitro studies with PAs and demonstrated stimulation of osteoblast differentiation and proliferation. On the other hand, adipogenesis was inhibited. To more fully understand the mechanistic actions of PAs on bone formation, we administered hippuric acid, one of the major metabolites found in animal circulation after BB consumption, to prepubertal female mice for 2 weeks. We found that hippuric acid was able to stimulate bone-forming gene expression but suppress PPAR? expression, leading to increased bone mass dose-dependently. Cellular signaling studies further suggested that the skeletal effects of PAs appeared to be mediated through activation of G-protein-coupled receptor 109A and downstream p38 MAP kinase and osterix. In conclusion, PAs are capable of altering the mesenchymal stem cell differentiation program and merit investigation as potential dietary therapeutic alternatives to drugs for degenerative bone disorders. © 2014 American Society for Bone and Mineral Research. PMID:23832484
Structurally modified fatty acids - clinical potential as tracers of metabolism
Dudczak, R.; Schmoliner, R.; Angelberger, P.; Knapp, F.F.; Goodman, M.M.
Recently 15-p-iodophenyl-betamethyl-pentadecanoic acid (BMPPA) was proposed for myocardial scintigraphy, as possible probe of metabolic processes other than ..beta..-oxidation. In 19 patients myocardial scintigraphy was done after i.v. BMPPA (2 to 4 mCi). Data were collected (LAO 45/sup 0//14; anterior/5) for 100 minutes in the fasted patients. From heart (H) and liver (L) organ to background (BG) ratios were calculated, and the elimination (E) behavior was analyzed from BG (V. cava region) corrected time activity curves. In 10 patients plasma and urine were examined. By CHCl/sub 3//MeOH extraction of plasma samples (90 min. pi) both in water and in organic medium soluble catabolites were found. TLC fractionation showed that those were co-migrating, compared to standards, with benzoic acid, BMPPA and triglycerides. In urine (0 to 2h pi: 4.1% dose) hippuric acid was found. It is concluded that BMPPA is a useful agent for myocardial scintigraphy. Its longer retention in the heart compared to unbranched radioiodinated fatty acids may facilitate SPECT studies. Rate of elimination and plasma analysis indicate the metabolic breakdown of BMPPA. Yet, the complexity of the supposed mechanism may impede curve interpretation in terms of specific metabolic pathways. 19 refs., 5 tabs.
A new perspective on the importance of glycine conjugation in the metabolism of aromatic acids.
Badenhorst, Christoffel Petrus Stephanus; Erasmus, Elardus; van der Sluis, Rencia; Nortje, Carla; van Dijk, Alberdina Aike
A number of endogenous and xenobiotic organic acids are conjugated to glycine, in animals ranging from mosquitoes to humans. Glycine conjugation has generally been assumed to be a detoxification mechanism, increasing the water solubility of organic acids in order to facilitate urinary excretion. However, the recently proposed glycine deportation hypothesis states that the role of the amino acid conjugations, including glycine conjugation, is to regulate systemic levels of amino acids that are also utilized as neurotransmitters in the central nervous systems of animals. This hypothesis is based on the observation that, compared to glucuronidation, glycine conjugation does not significantly increase the water solubility of aromatic acids. In this review it will be argued that the major role of glycine conjugation is to dispose of the end products of phenylpropionate metabolism. Furthermore, glucuronidation, which occurs in the endoplasmic reticulum, would not be ideal for the detoxification of free benzoate, which has been shown to accumulate in the mitochondrial matrix. Glycine conjugation, however, prevents accumulation of benzoic acid in the mitochondrial matrix by forming hippurate, a less lipophilic conjugate that can be more readily transported out of the mitochondria. Finally, it will be explained that the glycine conjugation of benzoate, a commonly used preservative, exacerbates the dietary deficiency of glycine in humans. Because the resulting shortage of glycine can negatively influence brain neurochemistry and the synthesis of collagen, nucleic acids, porphyrins, and other important metabolites, the risks of using benzoate as a preservative should not be underestimated. PMID:24754494
Urinary metabolites of flavonoids and hydroxycinnamic acids in humans after application of a crude extract from Equisetum arvense.
Graefe, E U; Veit, M
Flavonoids and hydroxycinnamic acids are polyphenolic compounds present in our daily diet in form of tea and vegetables as well as in herbal remedies used in phytomedicine. A wide range of in-vitro activities, in particular their antioxidant properties, have been studied intensively. However, in-vivo-data on absorption, bioavailability and metabolism after oral intake are scarce and contradictory. In order to examine the metabolism and renal excretion of these compounds a standardized extract from horsetail (Equisetum arvense) was administered to 11 volunteers following a flavonoid-free diet for 8 d. 24 h urine samples were collected and analyzed by HPLC-DAD. The putative quercetin metabolites, 3,4-dihydroxyphenylacetic acid or 3,4-dihydroxytoluene could not be detected in urine in any sample. The endogenous amount of homovanillic acid, generally regarded as one of the main quercetin metabolites, was 4 +/- 1 mg/d and did not increase significantly. However, hippuric acid, the glycine conjugate of benzoic acid, increased twofold after drug intake. Thus, the degradation to benzoic acid derivatives rather than phenylacetic acid derivatives seems to be a predominant route of metabolism. The results of this pilot study give rise to additional, substantial pharmacokinetic investigations in humans. PMID:10589442
Phenolic acid concentrations in plasma and urine from men consuming green or black tea and potential chemopreventive properties for colon cancer
Henning, Susanne M.; Wang, Piwen; Abgaryan, Narine; Vicinanza, Roberto; de Oliveira, Daniela Moura; Zhang, Yanjun; Lee, Ru-Po; Carpenter, Catherine L.; Aronson, William J.; Heber, David
Scope Tea polyphenols are metabolized by the colonic microflora yielding phenolic metabolites, which may contribute to the health benefits of tea. We determined the serum and urine concentrations of phenolic acids, hippuric acid and polyhydroxyphenyl-?-valerolactones during green tea (GT) and black tea (BT) administration. The effects of (?)-epigallocatechin gallate (EGCG) and 3,4-dihydroxyphenylacetic acid (3,4-DHPAA) alone and in combination on bioavailability, intracellular metabolism, and antiproliferative activity was determined in HCT-116 colon cancer cells. Methods and Results The concentration of phenolic metabolites was quantified by HPLC with electrochemical detection and MS. Urine concentrations of 4-hydroxyphenylacetic acid (4-HPAA), 3-hydroxyphenylacetic acid (3-HPAA) and polyhydroxy-?-valerolactones were increased significantly in men drinking GT compared to control. Urine concentration of 3-O-methylgallic acid (3OMGA) was significantly increased in men drinking BT compared to control. Serum 3,4-DHPAA was significantly increased after consumption of GT and BT and 4-HPAA after GT consumption. In vitro treatment of HCT-116 colon cancer cells with 3,4-DHPAA and EGCG exhibited an additive antiproliferative effect, while methylation of 3,4-DHPAA was significantly decreased. 3OMGA exhibited the strongest antiproliferative activity among the phenolic acids. Conclusions The consumption of both, GT and BT, was associated with a significant increase in urinary and serum phenolic acids. PMID:23319439
Metabolic profiling of phenolic acids and oxidative stress markers after consumption of Lonicera caerulea L. fruit.
Heinrich, Jan; Valentová, Kate?ina; Vacek, Jan; Palíková, Irena; Zatloukalová, Martina; Kosina, Pavel; Ulrichová, Jitka; Vrbková, Jana; Šimánek, Vilím
This study investigated the effect of one-week consumption of 165 g/day fresh blue honeysuckle berries (208 mg/day anthocyanins) in 10 healthy volunteers. At the end of intervention, levels of benzoic (median 1782 vs 4156), protocatechuic (709 vs 2417), vanillic (2779 vs 4753), 3-hydroxycinnamic (143 vs 351), p-coumaric (182 vs 271), isoferulic (805 vs 1570), ferulic (1086 vs 2395), and hippuric (194833 vs 398711 ?g/mg creatinine) acids by LC/MS were significantly increased in the urine. Clinical chemistry safety markers were not altered. Oxidative stress markers, erythrocyte glutathione peroxidase (0.73 vs 0.88 U/g Hb) and catalase (2.5 vs 2.8 ?kat/g Hb) activities, and erythrocyte/plasma thiobarbituric acid reactive substance (522 vs 612/33 vs 38 ?mol/g Hb/protein) levels were significantly increased, without change in plasma antioxidant status. Nonsignificant changes of advanced oxidation protein products and oxidized LDL were observed. The results provide a solid base for further study of metabolite excretion and antioxidant parameters after ingestion of anthocyanins. PMID:23581742
ERIC Educational Resources Information Center
Openshaw, Peter
Provides some background information on acid deposition. Includes a historical perspective, describes some effects of acid precipitation, and discusses acid rain in the United Kingdom. Contains several experiments that deal with the effects of acid rain on water quality and soil. (TW)
... Sciences NIH-HHS www.niehs.nih.gov Aristolochic Acids Key Points Report on Carcinogens Status Known to be human carcinogens Aristolochia Clematitis Aristolochic Acids n Known human carcinogens n Found in certain ...
Petersen, Maike; Simmonds, Monique S J
Rosmarinic acid is an ester of caffeic acid and 3,4-dihydroxyphenyllactic acid. It is commonly found in species of the Boraginaceae and the subfamily Nepetoideae of the Lamiaceae. However, it is also found in species of other higher plant families and in some fern and hornwort species. Rosmarinic acid has a number of interesting biological activities, e.g. antiviral, antibacterial, antiinflammatory and antioxidant. The presence of rosmarinic acid in medicinal plants, herbs and spices has beneficial and health promoting effects. In plants, rosmarinic acid is supposed to act as a preformed constitutively accumulated defence compound. The biosynthesis of rosmarinic acid starts with the amino acids L-phenylalanine and L-tyrosine. All eight enzymes involved in the biosynthesis are known and characterised and cDNAs of several of the involved genes have been isolated. Plant cell cultures, e.g. from Coleus blumei or Salvia officinalis, accumulate rosmarinic acid in amounts much higher than in the plant itself (up to 36% of the cell dry weight). For this reason a biotechnological production of rosmarinic acid with plant cell cultures has been proposed. PMID:12482446
NSDL National Science Digital Library
University of Houston,
Students learn the basics of acid/base chemistry in a fun, interactive way by studying instances of acid/base chemistry found in popular films such as Harry Potter and the Prisoner of Azkaban and National Treasure. Students learn what acids, bases and indicators are and how they can be used, including invisible ink. They also learn how engineers use acids and bases every day to better our quality of life. Students' interest is piqued by the use of popular culture in the classroom.
NSDL National Science Digital Library
Olivia Worland (Purdue University; Biological Sciences)
Baking soda can be used as an indicator of how much acid a substance contains. Lemons and limes have more acid in them than grapefruits and oranges. Indophenol can be used as an indicator of how much vitamin C is in a substance.
NSDL National Science Digital Library
Acids: this is a resource in the collection "General Chemistry Multimedia Problems". We will observe the reaction of sodium bicarbonate with three acid solutions. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.
NSDL National Science Digital Library
Bailey, Christina
This online student report discusses the chemistry of domoic acid, a biotoxin that is produced by the diatom Psuedo-nitzschia and associated with Amnesiac Shellfish Poisoning (ASP). In addition to a descriptive summary and images, the report links to other areas of interest related to domoic acid poisoning including signs and symptoms, modes of action, and treatment.
White, J.C. (Cornell University, Ithaca, NY (US))
This book presents the proceedings of the third annual conference sponsored by the Acid Rain Information Clearinghouse (ARIC). Topics covered include: Legal aspects of the source-receptor relationship: an energy perspective; Scientific uncertainty, agency inaction, and the courts; and Acid rain: the emerging legal framework.
Gene E. Likens; Richard F. Wright; James N. Galloway; Thomas J. Butler
Measurements of the acidity of rain and snow reveal that in parts of the eastern U.S. and of western Europe precipitation has changed from a nearly neutral solution 200 years ago to a dilute solution of sulfuric and nitric acids today. The trend is a result of the emission of sulfur and nitrogen oxides to the atmosphere accompanying the rise
Elsworth, S.
This book was written in a concise and readable style for the lay public. It's purpose was to make the public aware of the damage caused by acid rain and to mobilize public opinion to favor the elimination of the causes of acid rain.
NSDL National Science Digital Library
Tyser, Jim
Acid precipitation will be defined. At different points in the lesson students will write balanced reactions for the formation acid precipitation from atmospheric sulfur and nitrogen oxides and the neutralization of acids by limestone. Students will determine which states are most at risk from acid precipitation and assess how that risk has changed from 1996 to 2006. Sources of atmospheric sulfur (burning of high-sulfur coal) and nitrogen oxides (automobile exhaust) will be listed. The buffering effect of limestone soils and its mitigating effect on acid precipitation will be discussed. Students will correlate these areas with sulfur and nitrogen oxide production, population, composition of coal fields, and soil composition. This resource includes both a teaching guide and student worksheets.
Mitchell, Stephen C; Waring, Rosemary H
Asparagusic acid (1,2-dithiolane-4-carboxylic acid) is a simple sulphur-containing 5-membered heterocyclic compound that appears unique to asparagus, though other dithiolane derivatives have been identified in non-food species. This molecule, apparently innocuous toxicologically to man, is the most probable culprit responsible for the curious excretion of odorous urine following asparagus ingestion. The presence of the two adjacent sulphur atoms leads to an enhanced chemical reactivity, endowing it with biological properties including the ability to substitute potentially for ?-lipoic acid in ?-keto-acid oxidation systems. This brief review collects the scattered data available in the literature concerning asparagusic acid and highlights its properties, intermediary metabolism and exploratory applications. PMID:24099657
MedlinePLUS Videos and Cool Tools
... register. I'm interested in: Pregnancy Baby growth & care Research Volunteer opportunities Advocacy in government For health ... acid During your pregnancy Your pregnant body Prenatal care Eating and nutrition Physical activity Emotional and life ...
Acid precipitation has become one of the major environmental problems of this decade. It is a challenge to scientists throughout the world. Researchers from such diverse disciplines as plant pathology, soil science, bacteriology, meteorology and engineering are investigating diff...
Birti?, Simona; Dussort, Pierre; Pierre, François-Xavier; Bily, Antoine C; Roller, Marc
Carnosic acid (salvin), which possesses antioxidative and antimicrobial properties, is increasingly exploited within the food, nutritional health and cosmetics industries. Since its first extraction from a Salvia species (?70years ago) and its identification (?50years ago), numerous articles and patents (?400) have been published on specific food and medicinal applications of Rosmarinus and Salvia plant extracts abundant in carnosic acid. In contrast, relevant biochemical, physiological or molecular studies in planta have remained rare. In this overview, recent advances in understanding of carnosic acid distribution, biosynthesis, accumulation and role in planta, and its applications are summarised. We also discuss the deficiencies in our understanding of the relevant biochemical processes, and suggest the molecular targets of carnosic acid. Finally, future perspectives and studies related to its potential roles are highlighted. PMID:25639596
Martin, H.C.
At the International Symposium on Acidic Precipitation, over 400 papers were presented, and nearly 200 of them are included here. They provide an overview of the present state of the art of acid rain research. The Conference focused on atmospheric science (monitoring, source-receptor relationships), aquatic effects (marine eutrophication, lake acidification, impacts on plant and fish populations), and terrestrial effects (forest decline, soil acidification, etc.).
NSDL National Science Digital Library
Science Netlinks
This Science NetLinks lesson is intended for a high-school, introductory chemistry class or health class. The lesson begins with an article on the history of the development of aspirin. Students will then complete a lab that compares the reaction of regular aspirin, buffered aspirin, and enteric aspirin in neutral, acidic, and basic solutions. They will then analyze the results of the experiment to gain insight into how this information was used by researchers to solve some of the problems associated with aspirin. To complete the lesson, students must understand acids and bases.
ERIC Educational Resources Information Center
Young, Jay A.
A chemical laboratory information profile (CLIP) is presented for the chemical, stearic acid. The profile lists the chemical's physical and harmful characteristics, exposure limits, and symptoms of major exposure, for the benefit of teachers and students, who use the chemical in the laboratory.
... lifelong disabilities. They may also need many surgeries. Anencephaly (an-en-SEF-uh-lee), which is when most or all of the brain does not develop. Babies with this problem die before or shortly after birth. The results of some studies suggest that folic acid might also help to prevent other types of ...
NSDL National Science Digital Library
This activity is part of Planet Diary and is an online examination into acid rain and sulfur dioxide emissions. Students research which states have succeeded in reducing sulfur dioxide emissions between 1980 and 1999, and which states emissions have increased. This activity is accompanied by a page of websites for further information.
NSDL National Science Digital Library
In this activity, students explore the effect of chemical erosion on statues and monuments. They use chalk to see what happens when limestone is placed in liquids with different pH values. They also learn several things that engineers are doing to reduce the effects of acid rain.
Nazzaro-Porro, M
This review is an update on the literature accumulated over the past 10 years following the original observation that azelaic acid, a naturally occurring and nontoxic C9 dicarboxylic acid, possesses significant biologic properties and a potential as a therapeutic agent. These studies have shown that azelaic acid is a reversible inhibitor of tyrosinase and other oxidoreductases in vitro and that it inhibits mitochondrial respiration. It can also inhibit anaerobic glycolysis. Both in vitro and in vivo it has an antimicrobial effect on both aerobic and anaerobic (Propionibacterium acnes) microorganisms. In tissue culture it exerts a dose- and time-dependent cytotoxic effect on malignant melanocytes, associated with mitochondrial damage and inhibition of deoxyribonucleic acid (DNA) synthesis. Tumoral cell lines not containing tyrosinase are equally affected. Normal cells in culture exposed to the same concentrations of the diacid that are toxic for tumoral cells are in general not damaged. Radioactive azelaic acid has been shown to penetrate tumoral cells at a higher level than normal cells of the corresponding line. Topically applied (a 20% cream), it has been shown to be of therapeutic value in skin disorders of different etiologies. Its beneficial effect on various forms of acne (comedogenic, papulopustular, nodulocystic) has been clearly demonstrated. Particularly important is its action on abnormal melanocytes, which has led to the possibility of obtaining good results on melasma and highly durable therapeutic responses on lentigo maligna. It is also capable of causing regression of cutaneous malignant melanoma, but its role in melanoma therapy remains to be investigated.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:2963038
Pharmacology of oleanolic acid and ursolic acid
Jie Liu
Oleanolic acid and ursolic acid are triterpenoid compounds that exist widely in food, medicinal herbs and other plants. This review summarizes the pharmacological studies on these two triterpenoids. Both oleanolic acid and ursolic acid are effective in protecting against chemically induced liver injury in laboratory animals. Oleanolic acid has been marketed in China as an oral drug for human liver
NSDL National Science Digital Library
This highly detailed chemical information page features domoic acid, a toxin associated with Amnesic shellfish poisoning and naturally produced by the red algae Chondria armata and diatoms of the genus Pseudo-nitzschia. Created by the International Programme on Chemical Safety, this web page organizes information under the following sections: Name, Summary, Physio-Chemical Properties, Uses, Routes of Entry, Kinetics, Toxicology, Toxicological and Biomedical Investigations, Clinical Effects, Management, Illustrative Cases, Additional Information, References, and Authors.
ERIC Educational Resources Information Center
Damonte, Kathleen
The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. To understand what acid rain is, it is first necessary to know what an acid is. Acids can be defined as substances that produce hydrogen ions (H+), when dissolved in water. Scientists indicate how acidic a substance is by a set of numbers called the pH…
Technology Transfer Automated Retrieval System (TEKTRAN)
Many oxygenated fatty acids are bioactive compounds. Nocardia cholesterolicum and Flavobacterium DS5 convert oleic acid to 10 hydroxy stearic acid and linoleic acid to 10-hydroxy-12(Z)-octadecanoic acid. Pseudomonas aeruginosa PR3 converts oleic acid to new compounds, 7,10-dihydroxy-8(E)-octadecen...
NSDL National Science Digital Library
The I2I-Acid Ocean virtual lab is an e-learning activity where students become virtual scientists studying the impact of ocean acidification on sea urchin larval growth. Students recreate a real, up-to-date climate change experiment. They also learn important general scientific principles, such as the importance of sample size and numbers of replicates, and discuss what this research into a specific impact of climate change may mean for the future of our oceans. There is a French translation available.
Brnsted Acids The Strongest Isolable Acid**
Reed, Christopher A.
Brřnsted Acids The Strongest Isolable Acid** Mark Juhasz, Stephan Hoffmann, Evgenii Stoyanov, Kee-Chan Kim, and Christopher A. Reed* Acids based on carborane anions as conjugate bases (Figure 1) are a new class of Brřnsted (protic) acids, notable for their "strong yet gentle" qualities.[1] For example
Boyle, R.H.; Boyle, R.A.
Acid rain, says Boyle is a chemical leprosy eating into the face of North America and Europe, perhaps the major ecological problem of our time. Boyle describes the causes and scope of the phenomenon; the effects on man, wildlife, water, and our cultural heritage. He probes the delays of politicians and the frequent self-serving arguments advanced by industry in the face of what scientists have proved. The solutions he offers are to strengthen the Clean Air Act and require emission reductions that can be accomplished by establishing emission standards on a regional or bubble basis, burn low-sulfur coal, install scrubbers at critical plants, and invest in alternative energy sources. 73 references, 1 figure.
Illinois at Urbana-Champaign, University of
Formic Acid Fire Ant Starch Mechanical, Industrial Chemical, Petroleum Biological What Do and engineering. Products will range from starch, to polylactic acid, to corn fiber, to motor fuels. Progressive systems. Fire ants make formic acid. U of I researchers are developing fuel cells that use formic acid (1
ERIC Educational Resources Information Center
Hunger, Carolyn; And Others
Acid rain is a complex, worldwide environmental problem. This study guide is intended to aid teachers of grades 4-12 to help their students understand what acid rain is, why it is a problem, and what possible solutions exist. The document contains specific sections on: (1) the various terms used in conjunction with acid rain (such as acid…
NSDL National Science Digital Library
Acids and Bases: this is a resource in the collection "Netorials". In this module there is an introduction to the chemical properties of acids and bases. Afterwards, the sections include topics such as Molecular Structures of Acids and Bases, Ionization constants, properties of salts, buffers and Lewis theory of Acids and Bases. The Netorials cover selected topics in first-year chemistry including: Chemical Reactions, Stoichiometry, Thermodynamics, Intermolecular Forces, Acids & Bases, Biomolecules, and Electrochemistry.
Cyclic fatty acids from linolenic acid
R. A. Eisenhauer; R. E. Beal; E. L. Griffin
Linolenic acid of 95% purity was heated with excess alkali in ethylene glycol to produce cyclic fatty acids. Reaction variables,\\u000a which are associated with the cyclization reaction and which were investigated, included solvent-to-fatty-acid ratio, catalyst\\u000a concentration, and reaction temperature, headspace gas (N2 or C2H4), and head-space gas pressure.\\u000a \\u000a Yields of cyclic acids were improved by increasing solvent ratio (1.5–6 wt
Acid Thunder: Acid Rain and Ancient Mesoamerica
ERIC Educational Resources Information Center
Kahl, Jonathan D. W.; Berg, Craig A.
Much of Mesoamerica's rich cultural heritage is slowly eroding because of acid rain. Just as water dissolves an Alka-Seltzer tablet, acid rain erodes the limestone surfaces of Mexican archaeological sites at a rate of about one-half millimeter per century (Bravo et al. 2003). A half-millimeter may not seem like much, but at this pace, a few…
Lactate test ... test. Exercise can cause a temporary increase in lactic acid levels. ... not getting enough oxygen. Conditions that can increase lactic acid levels include: Heart failure Liver disease Lung disease ...
Plasma amino acids is a screening test done on infants that looks at the amounts of amino ... Laboratory error High or low amounts of individual plasma amino acids must be considered with other information. ...
Somerville, Chris (Portola Valley, CA); Broun, Pierre (Burlingame, CA); van de Loo, Frank (Lexington, KY)
This invention relates to plant fatty acyl hydroxylases. Methods to use conserved amino acid or nucleotide sequences to obtain plant fatty acyl hydroxylases are described. Also described is the use of cDNA clones encoding a plant hydroxylase to produce a family of hydroxylated fatty acids in transgenic plants. In addition, the use of genes encoding fatty acid hydroxylases or desaturases to alter the level of lipid fatty acid unsaturation in transgenic plants is described.
Dendritic Cells Hyaluronic Acid
Schüler, Axel
Keywords Dendritic Cells Hyaluronic Acid CD44 Human CD90 Melanoma » Prof. Dr. Jan C. Simon the role of HYALURONIC ACID (HA) and small fragments of HA during DC activation and the participating receptors on DC. (ii) Investigation of the extracellular glucosaminoglycan HYALURONIC ACID, its metabolism
NSDL National Science Digital Library
Learners use their knowledge of color changes with red cabbage indicator to neutralize an acidic solution with a base and then neutralize a basic solution with an acid. Use this as a follow-up activity to the related activity, "Color Changes with Acids and Bases."
ERIC Educational Resources Information Center
Kerber, Robert C.; Fernando, Marian S.
Several [alpha]-oxocarboxylic acids play key roles in metabolism in plants and animals. However, there are inconsistencies between the structures as commonly portrayed and the reported acid ionization constants, which result because the acids are predominantly hydrated in aqueous solution; that is, the predominant form is RC(OH)[subscript 2]COOH…
Anaerobic Amino Acid Metabolism
R. Reggiani; A. Bertani
Anoxic stress induces a strong change in sugar, protein, and amino acid metabolism in higher plants. Sugars are rapidly consumed through the anaerobic glycolysis to sustain energy production. Protein degradation under anoxia is a mechanism to release free amino acids contributing in this way to maintaining the osmotic potential of the tissue under stress. Among free amino acids, a particular
ERIC Educational Resources Information Center
Stubbs, Harriett S.; And Others
A topic which is often not sufficiently dealt with in elementary school textbooks is acid rain. This student text is designed to supplement classroom materials on the topic. Discussed are: (1) "Rain"; (2) "Water Cycle"; (3) "Fossil Fuels"; (4) "Air Pollution"; (5) "Superstacks"; (6) "Acid/Neutral/Bases"; (7) "pH Scale"; (8) "Acid Rain"; (9)…
ERIC Educational Resources Information Center
Likens, Gene E.
Acid rain is the collective term for any type of acidified precipitation: rain, snow, sleet, and hail, as well as the presence of acidifying gases, particles, cloud water, and fog in the atmosphere. The increased acidity, primarily from sulfuric and nitric acids, is generated as a by-product of the combustion of fossil fuels such as coal and oil.…
Nitrogen metabolism of early lactation cows fed diets with two different levels of protein and different amino acid profiles.
Bach, A; Huntington, G B; Calsamiglia, S; Stern, M D
Four multiparous Holstein cows (569+/-122 kg) surgically prepared with indwelling catheters in the mesenteric, portal, and hepatic veins and carotid artery were allocated in a 4 x 4 Latin square to determine the effects of dietary crude protein (CP) level and amino acid (AA) profile on N metabolism during early lactation (from 25 to 65 d in milk). Cows received their diets in two equal meals and were milked twice daily. The dietary treatments were: 18% CP with a high (18H) or a low (18L) quality AA profile, and 15% CP with a high (15H) or a low (15L) quality AA profile. The four diets were similar in net energy for lactation (1.75 NEL Mcal/kg) and contained the same amount of RUP (34% of CP). The quality of the AA profile pertained only to the essential AA (EAA), and was assessed by comparison with the EAA profile of casein and considered the potential contribution of EAA from ruminal bacteria. The 18H and 15H diets were supplemented with 50 and 25 g/d of ruminally protected Met, respectively. After 10 d on treatment, a blood flow marker (p-amino-hippurate) was infused into a mesenteric vein, and arterial, portal, hepatic, and mammary blood samples were obtained at 3, 6, and 12 h after feeding. Dry matter intake was similar across treatments (23.4+/-0.5 kg/d). Amino acid oxidation, and consequent urea production, in the liver were numerically greater with the 18% CP rations, and, as a result, arterial urea concentrations were greatest (P < 0.01) with these rations. The amount of total AA extracted by the mammary gland tended to be greater with the H than with the L diets (21.4 vs. 18.2 mmol/ h, respectively). Milk yield tended to be greater (P = 0.16) with the 18H and 15H diets (47.7 and 46.3 kg/d, respectively) compared with the 18L and 15L diets (45.9 and 44.6 kg/d, respectively). Also, milk CP and casein contents were greatest (P = 0.09) with the H diets compared with the L diets. Milk and plasma urea N were greatest (P < 0.01) with the 18% CP diets. The efficiency of N utilization for milk protein synthesis was greatest (P < 0.09) with the 15% CP diets. It is concluded that milk protein production during early lactation is less susceptible to variations in dietary CP contents than variations in the AA profile of the dietary protein. PMID:11104279
Prudent, James R.; Hall, Jeff G.; Lyamichev, Victor I.; Brow, Mary Ann; Dahlberg, James E.
The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.
Prudent, James R. (Madison, WI); Hall, Jeff G. (Waunakee, WI); Lyamichev, Victor I. (Madison, WI); Brow; Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)
The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.
Nucleic acid detection compositions
Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann (Madison, WI); Dahlberg, James L. (Madison, WI)
The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.
Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor L. (Madison, WI); Brow, Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)
The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.
Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)
The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.
This editorial focuses on acid rain and the history of public and governmental response to acid rain. Comments on a book by Gwineth Howell `Acid Rain and Acid Waters` are included. The editor feels that Howells has provide a service to the environmental scientific community, with a textbook useful to a range of people, as well as a call for decision makers to learn from the acid rain issue and use it as a model for more sweeping global environmental issues. A balance is needed among several parameters such as level of evidence, probability that the evidence will lead to a specific direction and the cost to the global community. 1 tab.
NASA Technical Reports Server (NTRS)
Winitz, M.; Graff, J. (inventors)
The process and apparatus for qualitative and quantitative analysis of the amino acid content of a biological sample are presented. The sample is deposited on a cation exchange resin and then is washed with suitable solvents. The amino acids and various cations and organic material with a basic function remain on the resin. The resin is eluted with an acid eluant, and the eluate containing the amino acids is transferred to a reaction vessel where the eluant is removed. Final analysis of the purified acylated amino acid esters is accomplished by gas-liquid chromatographic techniques.
Process for the preparation of lactic acid and glyceric acid
Jackson, James E [Haslett, MI; Miller, Dennis J [Okemos, MI; Marincean, Simona [Dewitt, MI
Hexose and pentose monosaccharides are degraded to lactic acid and glyceric acid in an aqueous solution in the presence of an excess of a strongly anionic exchange resin, such as AMBERLITE IRN78 and AMBERLITE IRA400. The glyceric acid and lactic acid can be separated from the aqueous solution. Lactic acid and glyceric acid are staple articles of commerce.
The linoleic acid and trans fatty acids of margarines1
J. L. Beare-Rogers; L. M. Gray; R. Hollywood
Fifty brands of margarine were analysed for cis-polyunsaturated acids by lipox- idase, for trans fatty acid by infrared spectroscopy, and for fatty acid composition by gas-liquid chromatography. High concentrations of trans fatty acids tended to be associated with low concentrations of hinoleic acid. Later analyses on eight of the brands, representing various proportions of linoleic to trans fatty acids, indicated
78 FR 20029 - Castor Oil, Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic Acid; Tolerance...
Federal Register 2010, 2011, 2012, 2013, 2014
...AGENCY 40 CFR Part 180 [EPA-HQ-OPP-2013-0057; FRL-9381-2] Castor Oil, Polymer With Adipic Acid, Linoleic Acid, Oleic Acid and Ricinoleic Acid; Tolerance Exemption AGENCY: Environmental Protection Agency (EPA). ACTION:...
Kornprobst, Jean-Michel; Barnathan, Gilles
The well-known fatty acids with a ?5,9 unsaturation system were designated for a long period as demospongic acids, taking into account that they originally occurred in marine Demospongia sponges. However, such acids have also been observed in various marine sources with a large range of chain-lengths (C16–C32) and from some terrestrial plants with short acyl chains (C18–C19). Finally, the ?5,9 fatty acids appear to be a particular type of non-methylene-interrupted fatty acids (NMA FAs). This article reviews the occurrence of these particular fatty acids in marine and terrestrial organisms and shows the biosynthetic connections between ?5,9 fatty acids and other NMI FAs. PMID:21116406
Hall, Jeff G.; Lyamichev, Victor I.; Mast, Andrea L.; Brow, Mary Ann; Kwiatkowski, Robert W.; Vavra, Stephanie H.
The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof. The present invention further relates to methods and devices for the separation of nucleic acid molecules based on charge. The present invention also provides methods for the detection of non-target cleavage products via the formation of a complete and activated protein binding region. The invention further provides sensitive and specific methods for the detection of nucleic acid from various viruses in a sample.
Microorganisms for producing organic acids
Pfleger, Brian Frederick; Begemann, Matthew Brett
Organic acid-producing microorganisms and methods of using same. The organic acid-producing microorganisms comprise modifications that reduce or ablate AcsA activity or AcsA homolog activity. The modifications increase tolerance of the microorganisms to such organic acids as 3-hydroxypropionic acid, acrylic acid, propionic acid, lactic acid, and others. Further modifications to the microorganisms increase production of such organic acids as 3-hydroxypropionic acid, lactate, and others. Methods of producing such organic acids as 3-hydroxypropionic acid, lactate, and others with the modified microorganisms are provided. Methods of using acsA or homologs thereof as counter-selectable markers are also provided.
Prediction of Effective Acid Penetration and Acid Volume for Matrix Acidizing Treatments in Naturally Fractured Carbonates
Xiong Hongjie
This paper discusses a new method and a corresponding computer model developed to investigate matrix acidizing in naturally fractured carbonates. With this method, the effective acid penetration distance and acid volume needed for acid treatments in naturally fractured carbonates can be predicted. The new model simulates acid flowing in the natural fracture network and the acid\\/rock reaction. During the simulation,
Wurtman, Richard
CHRONIC ADMINISTRATION OF DOCOSAHEXAENOIC ACID OR EICOSAPENTAENOIC ACID, BUT NOT ARACHIDONIC ACID circulating precursors: choline; a pyrimidine (e.g. uridine); and a poly- unsaturated fatty acid, with UMP plus the omega-3 fatty acid docosa- hexaenoic acid (given by gavage), produces substantial in
NSDL National Science Digital Library
These suggestions for activities allow students to learn about acid deposition in new and interactive ways, both in and out of the classroom. The suggestions are for individuals and small groups, the class as a whole, or for field trips. Students may contact local experts about acid rain issues, investigate the energy sources used to generate electricity by their local power companies, collect cartoons about acid rain and air pollution, or play the roles of scientists or interested parties involved in investigations of acid rain issues. Field trip ideas include visiting a local museum or science center to see exhibits or resources on acid rain, and visiting a local cemetary to examine the effects of acid rain on the headstones.
François Verrey; Dustin Singer; Tamara Ramadan; Raphael N. Vuille-dit-Bille; Luca Mariotta; Simone M. R. Camargo
Near complete reabsorption of filtered amino acids is a main specialized transport function of the kidney proximal tubule.\\u000a This evolutionary conserved task is carried out by a subset of luminal and basolateral transporters that together form the\\u000a transcellular amino acid transport machinery similar to that of small intestine. A number of other amino acid transporters\\u000a expressed in the basolateral membrane
John Y. L. Chiang
\\u000a Bile acids are physiological agents that facilitate biliary secretion of lipids and metabolites, and intestinal absorption\\u000a of fat and nutrients. Bile acids are also signaling molecules that activate nuclear receptors and cell signaling pathways\\u000a to regulate hepatic lipid metabolism and homeostasis. Bile acids are synthesized from cholesterol in the liver, stored in\\u000a the gallbladder, secreted to the intestine and reabsorbed
Timothy Jickells; Anthony Knap; Thomas Church; James Galloway; John Miller
Increased acidity of precipitation due to combustion of fossil fuels has been well documented for both the eastern USA1 and Canada2. The SO2 and NOxemitted by the burning of coal, natural gas, fuel oil and petrol are oxidized in the atmosphere to sulphuric and nitric acids which subsequently give rise to acid precipitation1. However, the SO2 and NOx emitted, and
NSDL National Science Digital Library
This on-line exercise is focused on lactic acid bacteria, a group of related bacteria that produce lactic acid as a result of carbohydrate fermentation. It includes a protocol for the enrichment of lactic acid bacteria from enriched samples (like yogurt, sauerkraut, decaying plant matter, and tooth plaque). Three parameters are measured: growth, culture diversity, and pH. The exercise also includes instructions for the isolation of some of these bacteria by using the streak-plate method.
Molecular Structure of Fumaric acid
NSDL National Science Digital Library
Fumaric acid is odorless and colorless or white crystalline powder with a fruit acid taste. Fumaric acid is used as a substitute of tartaric acid in beverages and baking powders and as a replacement for citric acid in fruits drinks. It is also used as antioxidant to prevent rancidity in butter, cheese, powdered milk, and other foodstuff. In addition, fumaric acid is a chemical intermediate in the manufacture of pharmaceuticals, synthetic resins and plastics. Fumaric acid can be prepared by catalytic oxidation of benzene or by bacterial action on glucose and it is involved in the production of energy from food. Fumaric acid (known as trans-butanedioic acid) is the trans isomer of maleic acid (also called cis-butanedioic acid). Fumaric acid is more stable than maleic acid and can be prepared by heating maleic acid.
Verser, Dan W. (Golden, CO); Eggeman, Timothy J. (Lakewood, CO)
A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.
Verser, Dan W. (Menlo Park, CA); Eggeman, Timothy J. (Lakewood, CO)
A method is disclosed for the recovery of an organic acid from a dilute salt solution in which the cation of the salt forms an insoluble carbonate salt. A tertiary amine and CO.sub.2 are introduced to the solution to form the insoluble carbonate salt and a complex between the acid and an amine. A water immiscible solvent, such as an alcohol, is added to extract the acid/amine complex from the dilute salt solution to a reaction phase. The reaction phase is continuously dried and a product between the acid and the solvent, such as an ester, is formed.
Idiopathic bile acid catharsis.
Thaysen, E H; Pedersen, L
In the course of extensive routine screening for bile acid malabsorption a few patients were detected in whom chronic diarrhoea was apparently induced by excess bile acid loss which was neither associated with demonstrable conventional ileopathy nor with any other disorder allied to diarrhoea. In three patients subjected to scrutiny the results obtained were in harmony with a concept of idiopathic bile acid catharsis. Ingestion of cholestyramine was followed by immediate relief, but the diarrhoea recurred whenever this treatment was withdrawn. It it suggested that idiopathic bile acid catharsis should be suspected in patients with unexplained chronic diarrhoea and especially in those with a diagnosis of irritable colon with diarrhoea. PMID:1017717
Gordon, John D.; Nilles, Mark A.; Schroder, LeRoy J.
The U.S. Geological Survey (USGS) has been actively studying acid rain for the past 15 years. When scientists learned that acid rain could harm fish, fear of damage to our natural environment from acid rain concerned the American public. Research by USGS scientists and other groups began to show that the processes resulting in acid rain are very complex. Scientists were puzzled by the fact that in some cases it was difficult to demonstrate that the pollution from automobiles and factories was causing streams or lakes to become more acidic. Further experiments showed how the natural ability of many soils to neutralize acids would reduce the effects of acid rain in some locations--at least as long as the neutralizing ability lasted (Young, 1991). The USGS has played a key role in establishing and maintaining the only nationwide network of acid rain monitoring stations. This program is called the National Atmospheric Deposition Program/National Trends Network (NADP/NTN). Each week, at approximately 220 NADP/NTN sites across the country, rain and snow samples are collected for analysis. NADP/NTN site in Montana. The USGS supports about 72 of these sites. The information gained from monitoring the chemistry of our nation's rain and snow is important for testing the results of pollution control laws on acid rain.
NSDL National Science Digital Library
The EPA developed this colorful website to teach students all about acid rain. First, through clear descriptions and helpful figures users can learn the characteristics of acid rain, its dangers, and how to control it. The website offers an interactive connect-the-dots, word searches, crossword puzzles, and other games. A short movie provides an overview of how the use of coal contributes to acid rain and acid rain's impacts on ecosystems and human health. The website also offers an introduction to the pH scale and tools to measure the pH.
Silicic acid: boric acid complexes as wood preservatives
Haruhiko Yamaguchi
Wood was treated with a low molecular-weight silicic acid: boric acid agent and examined for increased resistance to termites and combustion. Wood treated with silicic acid only exhibited increased termite resistance, but not to the marked extent observed after treatment with a mixture of silicic and boric acids. Increasing the quantity of boric acid also increased the termite mortality rate
Ambient monitoring of acid aerosol in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. easurements made in Kingston, TN, and Stuebenville, OH, resulted in 24-hr H+ ion concentrations exceeding 100 nmole/m3 more than 10 ti...
Technology Transfer Automated Retrieval System (TEKTRAN)
Proteins are the most abundant substances in living organisms and cells. All proteins are constructed from the same twenty amino acids that are linked together by covalent bonds. Shorter chains of two or more amino acids can be linked by covalent bonds to form polypeptides. There are twenty amino...
Tautomerism of Penicillic Acid
C. W. Munday
THE existence of tautomeric forms of penicillic acid was first postulated by Birkinshaw, Oxford arid Raistrick1. Recent workers have tended to the view that the hypothesis of tautomerism was not needed to explain the chemical properties of penicillic acid2.
Propa pH® Peel-Off Acne Mask ... pimples and skin blemishes in people who have acne. Topical salicylic acid is also used to treat ... medications called keratolytic agents. Topical salicylic acid treats acne by reducing swelling and redness and unplugging blocked ...
NSDL National Science Digital Library
Strong Acids: this is a resource in the collection "General Chemistry Multimedia Problems". This problem will explore the properties of common strong acids. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.
NSDL National Science Digital Library
Acids and Salts: this is a resource in the collection "General Chemistry Multimedia Problems". This problem will explore a few properties of common acids and their salts. General Chemistry Multimedia Problems ask students questions about experiments they see presented using videos and images. The questions asked apply concepts from different parts of an introductory course, encouraging students to decompartmentalize the material.
ERIC Educational Resources Information Center
Sims, Paul A.
Learning the 20 standard amino acids is an essential component of an introductory course in biochemistry. Later in the course, the students study metabolism and learn about various catabolic and anabolic pathways involving amino acids. Learning new material or concepts often is easier if one can connect the new material to what one already knows;…
Fay, James A.
High concentrations of sulfuric and nitric acid in raTn fn the northeastern USA are caused by the large scale combustion of fossil fuels within this region. Average precipitation acidity is pH 4.2, but spatial and temporal ...
NSDL National Science Digital Library
The phenomenon is the formation of acid rain. The resource explains the chemical reaction that begins when compounds like sulfur dioxide and nitrogen oxides are released into the air, mix and react with water and other chemicals to form more acidic pollutants that dissolve very easily in water and can be carried long distances where they become part of rain, sleet, snow, and fog.
Recent reviews of available data indicate that precipitation in a large region of North America is highly acidic when its pH is compared with the expected pH value of 5.65 for pure rain water in equilibrium with CO2. A growing body of evidence suggests that acid rain is responsib...
Characterization of acid tars.
Leonard, Sunday A; Stegemann, Julia A; Roy, Amitava
Acid tars from the processing of petroleum and petrochemicals using sulfuric acid were characterized by gas chromatography/mass spectrometry (GC/MS), inductively coupled plasma/optical emission spectrometry (ICP/OES), differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectrometry, and scanning electron microscopy/energy dispersive X-ray (SEM/EDX) micro-analysis. Leaching of contaminants from the acid tars in 48 h batch tests with distilled water at a liquid-to-solid ratio 10:1 was also studied. GC/MS results show that the samples contained aliphatic hydrocarbons, cyclic hydrocarbons, up to 12 of the 16 USEPA priority polycyclic aromatic hydrocarbons (PAHs), and numerous other organic groups, including organic acids (sulfonic acids, carboxylic acids and aromatic acids), phenyl, nitrile, amide, furans, thiophenes, pyrroles, and phthalates, many of which are toxic. Metals analysis shows that Pb was present in significant concentration. DSC results show different transition peaks in the studied samples, demonstrating their complexity and variability. FTIR analysis further confirmed the presence of the organic groups detected by GC/MS. The SEM/EDX micro-analysis results provided insight on the surface characteristics of the samples and show that contaminants distribution was heterogeneous. The results provide useful data on the composition, complexity, and variability of acid tars; information which hitherto have been scarce in public domain. PMID:19857924
NSDL National Science Digital Library
Laszlo Ilyes (None; )
Plants and animals that live in water create some amount of acid in the water. The carbon dioxide that plants and animals release into the water makes the water acidic and unsafe for living organisms. This is why the water of captive aquatic animals and plants must be changed often.
ERIC Educational Resources Information Center
Griswold, John R.; Rauner, Richard A.
Presented are the procedures and a discussion of the results for an experiment in which students select unknown carboxylic acids, determine their melting points, and investigate their solubility behavior in water and ethanol. A table of selected carboxylic acids is included. (CW)
NSDL National Science Digital Library
Sanders, Hilary C.
The results of a long term study of the effects of acidic deposition in the Northeast were published in Bioscience this week, and they suggest that forests, lakes, and streams of the Northeastern US are not recovering from the toxic effects of acid rain despite significant cuts in the power plant emissions of sulfur dioxide and nitrogen oxide -- two major contributors to the problem. "Acid rain," more accurately called acidic deposition, causes toxic forms of aluminum to concentrate in soil and water, vital calcium and magnesium to be leached from trees, and surface waters to become inhospitable to aquatic biota. The study showed that, after 30 years of federally mandated air emission reductions, sulfur dioxide emissions have decreased while nitrogen oxide emissions have remained the same and that acidic deposition-related problems continue to plague New York and New England.
Sprenger, Norbert; Duncan, Peter I.
Early postnatal development encounters milk as a key environmental variable and yet the sole nutrient source. One evolutionary conserved constituent of milk is sialic acid, which is generally displayed on glycoconjugates and free glycans. During early postnatal development, high sialic acid need was proposed to be unmet by the endogenous sialic acid synthetic capacity. Hence, milk sialic acid was proposed to serve as a conditional nutrient for the newborn. In the elderly, at the other end of ontogeny, decreased sialylation in the brain, saliva, and immune system is observed. Analogous to the neonatal situation, the endogenous synthetic capacity may be unable to keep up with the need in this age group. The data discussed here propose a functional dietary role of sialic acid as a building block for sialylation and beyond. PMID:22585917
Simultaneous determination by gas chromatography of the major metabolites in urine of toluene, xylenes and styrene.
Van Roosmalen, P B; Drummond, I
A gas chromatographic method has been developed to determine the following metabolites in urine simultaneously if necessary: hippuric acid from toluene or styrene; 3- and 4-methyl hippuric acids from xylenes; phenylglyoxylic acid and mandelic acid from styrene. Heptadecanoic acid is added to the urine as an internal standard and after ethyl acetate extraction from acidic solution, the trimethylsilyl (TMS) derivatives of the metabolites are formed and simultaneously analysed by gas chromatography on 3% OV-1 on 80/100 gas chrom Q (flame ionisation detector). PMID:629890
Carboxylic Acid Unknowns and Titration 90 CARBOXYLIC ACID UNKNOWN
Jasperse, Craig P.
Carboxylic Acid Unknowns and Titration 90 CARBOXYLIC ACID UNKNOWN A. Solubility Tests: Water, Na the formula weight. #12;Carboxylic Acid Unknowns and Titration 91 Note: Do your titration once, and check
CLA production from ricinoleic acid by lactic acid bacteria
Akinori Ando; Jun Ogawa; Shigenobu Kishino; Sakayu Shimizu
The ability to produce CLA from ricinoleic acid is widely distributed in lactic acid bacteria. Washed cells of Lactobacillus plantarum JCM 1551 were selected as a potential catalyst for CLA production from ricinoleic acid. Cells cultivated in medium supplemented\\u000a with a mixture of ?-linolenic acid and linoleic acid showed enhanced CLA productivity. Under optimal reaction conditions,\\u000a with the free acid
Antioxidant activity of caffeic acid (3,4-dihydroxycinnamic acid)
?lhami Gülçin
Caffeic acid (3,4-dihydroxycinnamic acid) is among the major hydroxycinnamic acids present in wine; sinapic acid, which is a potent antioxidant. It has also been identified as one of the active antioxidant. In the present study, the antioxidant properties of the caffeic acid were evaluated by using different in vitro antioxidant assays such as 2-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) (ABTS) radical scavenging, 1,1-diphenyl-2-picryl-hydrazyl free
E. Montoneri; P. Savarino; G. Viscardi; M. C. Gallazzi
Four new organosulphur phosphorus acid compounds have been obtained by sulphonation with liquid SO3: 2-fluorobenzylphosphonic and 4-fluorobenzylphosphonic acids gave 2-fluorobenzylphosphono-5-sulphonic and 4-fluorobenzylphosphono-3-sulphonic acids respectively, in nearly quantitative yields; 3-fluorobenzylphosphonic acid gave 3-fluorobenzylphosphono-6-sulphonic acid (85%) and 3-fluorobenzylphosphono-4-sulphonic acid (15%). Product structures are based on C magnetic resonance data. The entry of the SO3H group into the aromatic ring seems mainly ruled
This Environmental Security Technology Certification Program (ESTCP) project demonstrated the Waste Acid Detoxification and Reclamation (WADR) systems ability to recover waste electropolish acid solutions generated during the manufacturing of gun-tubes, and reuse the clean acid. ...
Anastassiadis, Savas; Morgunov, Igor G
Gluconic acid, the oxidation product of glucose, is a mild neither caustic nor corrosive, non toxic and readily biodegradable organic acid of great interest for many applications. As a multifunctional carbonic acid belonging to the bulk chemicals and due to its physiological and chemical characteristics, gluconic acid itself, its salts (e.g. alkali metal salts, in especially sodium gluconate) and the gluconolactone form have found extensively versatile uses in the chemical, pharmaceutical, food, construction and other industries. Present review article presents the comprehensive information of patent bibliography for the production of gluconic acid and compares the advantages and disadvantages of known processes. Numerous manufacturing processes are described in the international bibliography and patent literature of the last 100 years for the production of gluconic acid from glucose, including chemical and electrochemical catalysis, enzymatic biocatalysis by free or immobilized enzymes in specialized enzyme bioreactors as well as discontinuous and continuous fermentation processes using free growing or immobilized cells of various microorganisms, including bacteria, yeast-like fungi and fungi. Alternatively, new superior fermentation processes have been developed and extensively described for the continuous and discontinuous production of gluconic acid by isolated strains of yeast-like mold Aureobasidium pullulans, offering numerous advantages over the traditional discontinuous fungi processes. PMID:19075839
NASA Astrophysics Data System (ADS)
Doyle, Ellin
Fats and their various fatty acid components seem to be a perennial concern of nutritionists and persons concerned with healthful diets. Advice on the consumption of saturated, polyunsaturated, monounsaturated, and total fat bombards us from magazines and newspapers. One of the newer players in this field is the group of trans fatty acids found predominantly in partially hydrogenated fats such as margarines and cooking fats. The controversy concerning dietary trans fatty acids was recently addressed in an American Heart Association (AHA) science advisory (1) and in a position paper from the American Society of Clinical Nutrition/American Institute of Nutrition (ASCN/AIN) (2). Both reports emphasize that the best preventive strategy for reducing risk for cardiovascular disease and some types of cancer is a reduction in total and saturated fats in the diet, but a reduction in the intake of trans fatty acids was also recommended. Although the actual health effects of trans fatty acids remain uncertain, experimental evidence indicates that consumption of trans fatty acids adversely affects serum lipid levels. Since elevated levels of serum cholesterol and triacylglycerols are associated with increased risk of cardiovascular disease, it follows that intake of trans fatty acids should be minimized.
NASA Technical Reports Server (NTRS)
1999-01-01Frozen sulfuric acid on Jupiter's moon Europa is depicted in this image produced from data gathered by NASA's Galileo spacecraft. The brightest areas, where the yellow is most intense, represent regions of high frozen sulfuric acid concentration. Sulfuric acid is found in battery acid and in Earth's acid rain. This image is based on data gathered by Galileo's near infrared mapping spectrometer.Europa's leading hemisphere is toward the bottom right, and there are enhanced concentrations of sulfuric acid in the trailing side of Europa (the upper left side of the image). This is the face of Europa that is struck by sulfur ions coming from Jupiter's innermost moon, Io. The long, narrow features that crisscross Europa also show sulfuric acid that may be from sulfurous material extruded in cracks. Galileo, launched in 1989, has been orbiting Jupiter and its moons since December 1995. JPL manages the Galileo mission for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.
Molecular Structure of Gallic acid
NSDL National Science Digital Library
Gallic acid is found in its free state and combined with the tannin molecule, from which it can be extracted by the hydrolysis of tannic acid with sulfuric acid. Since one molecule of gallic acid has a carboxylic acid group and hydroxyl groups, it can react with another molecule of gallic acid to form an ester, digallic acid. When heated above 200 degrees C, gallic acid loses carbon dioxide to form pyrogallol (1,2,3-trihydroxybenzene, C6H3(OH)3), which is used in the production of azo dyes, photographic developers, and in laboratories for absorbing oxygen.
... in combination with photodynamic therapy (PDT; special blue light) to treat actinic keratoses (small crusty or scaly ... photosensitizing agents. When aminolevulinic acid is activated by light, it damages the cells of actinic keratosis lesions.
NSDL National Science Digital Library
MD Alan W. Grogono (Tulane University School of Medicine Dept. of Anesthesiology)
Website for anyone wanting to become more familiar with the physiology of acid-base balance in clinical medicine. Several pages are interactive. Numerical results are accompanied by text interpretations to facilitate recognition and understanding.
Turk, Stacey N.
We hypothesized that subcutaneous (s.c.) adipose tissue would differ in monounsaturated (MUFA) and saturated fatty acid (SFA) composition among different depots throughout a beef carcass. To test this, 50 carcasses from a variety of breed types...
Gastric acid secretion test ... The test is done after a period of not eating so that fluid is all that remains in the ... the stomach through the esophagus (food pipe). To test the ability of the cells in the stomach ...
Amoxicillin and Clavulanic Acid
... is used to treat certain infections caused by bacteria, including infections of the ears, lungs, sinus, skin, ... antibiotics. It works by stopping the growth of bacteria. Clavulanic acid is in a class of medications ...
The paper discusses acid rain control options available to the electric utility industry. They include coal switching, flue gas desulfurization, and such emerging lower cost technologies as Limestone Injection Multistage Burners (LIMB) and Advanced Silicate (ADVACATE) both develo...
Difficult Decisions: Acid Rain.
ERIC Educational Resources Information Center
Miller, John A.; Slesnick, Irwin L.
Discusses some of the contributing factors and chemical reactions involved in the production of acid rain, its effects, and political issues pertaining to who should pay for the clean up. Supplies questions for consideration and discussion. (RT)
... show that an increase in the mother's dietary folic acid before conception and during the first month of pregnancy reduces the risk of having a child with a neural tube defect. The recommendation is that women of childbearing years ...
Diversity of Oleic Acid, Ricinoleic Acid and Linoleic Acid Conversions Among Pseudomonas aeruginosa Strains
Tsung Min Kuo; Lawrence K. Nakamura
Sixteen Pseudomonas aeruginosa strains, including patent strain NRRL B-18602, three recent isolates from composted materials amended with ricinoleic acid, and 12 randomly selected from the holdings of the ARS Culture Collection, were examined for their fatty acid converting abilities. The study examined the bioconversion of oleic acid to 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) and ricinoleic acid to 7,10,12-trihydroxy-8(E)-octadecenoic acid (TOD). A new
Folic Acid Recommendations Survey
S. A. Pinkham; K. Cobb
This study was designed to determine the current practices of women's health care providers with regard to folic acid knowledge and recommendations. Two-hundred-twenty obstetrician\\/gynecologists and certified nurse-midwives participated by completing questionnaires.A gap between the belief that folic acid reduces the risk of neural tube defects [NTDs] and the lack of widespread supplementation recommendations was revealed. Results showed that only 45%
Hand, C.W.; Blewit, H.L.
The book is not a research compendium and there are no references to the literature. It is a teaching text covering the entire range of undergraduate subject matter dealing with acid-base chemistry (some of it remotely) as taught in inorganic, analytical, and organic chemistry courses. The excellent chapters VII through IX deal in detail with the quantitative aspects of aqueous acid-base equilibria (salt hydrolysis and buffer, titrations, polyprotic and amphoteric substances).
NSDL National Science Digital Library
Five articulated lessons focus on air quality using classroom and field data collection activities. Case study in Great Smoky Mountains has broader application. Background and data for lessons on: the pH scale, understanding acid vs. base, collecting data, mapping relationship of weather events to acid rain. Links to NPS data on air quality, current values, atlas and reports, packaged datasets on ozone, meteorological conditions and other parameters. Also available: teacher resources; educator workshops.
Biodegradation of polyhydroxyalkanoic acids
D. Jendrossek; A. Schirmer; H. G. Schlegel
Stimulated by the commercial availability of bacteriologically produced polyesters such as poly[(R)-3-hydroxybutyric acid], and encouraged by the discovery of new constituents of polyhydroxyalkanoic acids (PHA), a considerable\\u000a body of knowledge on the metabolism of PHA in microorganisms has accumulated. The objective of this essay is to give an overview\\u000a on the biodegradation of PHA. The following topics are discussed: (i)
Thin-layer chromatography of gallic acid, methyl gallate, pyrogallol, phloroglucinol, catechol, resorcinol, hydroquinone, catechin, epicatechin, cinnamic acid, p-coumaric acid, ferulic acid and tannic acid
Om Prakash Sharma; Tej Krishan Bhat; Bhupinder Singh
Six solvent systems of varying suitability are reported for the thin-layer chromatographic separation of simple phenolics and related compounds such as gallic acid, methyl gallate, pyrogallol, phloroglucinol, catechol, resorcinol, hydroquinone, catechin, epicatechin, cinnamic acid, p-coumaric acid, ferulic acid and tannic acid. The solvent system chloroform-ethyl acetate-acetic acid (50:50:1) facilitated the separation of all the compounds except pyrogallol and ferulic acid;
Walters, Julian R. F.; Pattni, Sanjeev S.
Bowel symptoms including diarrhoea can be produced when excess bile acids (BA) are present in the colon. This condition, known as bile acid or bile salt malabsorption, has been under recognized, as the best diagnostic method, the 75Se-homocholic acid taurine (SeHCAT) test, is not available in many countries and is not fully utilized in others. Reduced SeHCAT retention establishes that this is a complication of many other gastrointestinal diseases. Repeated studies show SeHCAT tests are abnormal in about 30% of patients otherwise diagnosed as diarrhoea-predominant irritable bowel syndrome or functional diarrhoea, with an estimated population prevalence of around 1%. Recent work suggests that the condition previously called idiopathic bile acid malabsorption (BAM) is not in fact due to a defect in absorption, but results from an overproduction of BA because of defective feedback inhibition of hepatic bile acid synthesis, a function of the ileal hormone fibroblast growth factor 19 (FGF19). The approach to treatment currently depends on binding excess BA, to reduce their secretory actions, using colestyramine, colestipol and, most recently, colesevelam. Colesevelam has a number of potential advantages that merit further investigation in trials directed at patients with bile acid diarrhoea. PMID:21180614
Portable nucleic acid thermocyclers.
Almassian, David R; Cockrell, Lisa M; Nelson, William M
A nucleic acid thermal cycler is considered to be portable if it is under ten pounds, easily carried by one individual, and battery powered. Nucleic acid amplification includes both polymerase chain reaction (e.g. PCR, RT-PCR) and isothermal amplification (e.g. RPA, HDA, LAMP, NASBA, RCA, ICAN, SMART, SDA). There are valuable applications for portable nucleic acid thermocyclers in fields that include clinical diagnostics, biothreat detection, and veterinary testing. A system that is portable allows for the distributed detection of targets at the point of care and a reduction of the time from sample to answer. The designer of a portable nucleic acid thermocycler must carefully consider both thermal control and the detection of amplification. In addition to thermal control and detection, the designer may consider the integration of a sample preparation subsystem with the nucleic acid thermocycler. There are a variety of technologies that can achieve accurate thermal control and the detection of nucleic acid amplification. Important evaluation criteria for each technology include maturity, power requirements, cost, sensitivity, speed, and manufacturability. Ultimately the needs of a particular market will lead to user requirements that drive the decision between available technologies. PMID:24030680
Original article Acid stress susceptibility and acid adaptation
Paris-Sud XI, Université de
Original article Acid stress susceptibility and acid adaptation of Propionibacterium freudenreichii as their use in cheese tech- nology implies exposure to various environmental stresses, including acidic pH. The acid tolerance response (ATR) of Propionibacterium freudenreichii was investigated. One strain present
Acid Rain, pH & Acidity: A Common Misinterpretation.
ERIC Educational Resources Information Center
Clark, David B.; Thompson, Ronald E.
Illustrates the basis for misleading statements about the relationship between pH and acid content in acid rain. Explains why pH cannot be used as a measure of acidity for rain or any other solution. Suggests that teachers present acidity and pH as two separate and distinct concepts. (RT)
What is Acid Rain? Explore the Acid Lake
NSDL National Science Digital Library
Earth Day Canada
Acid rain is a type of air pollution that occurs when certain chemicals mix with water in the air. Most chemicals that cause acid rain come from the emissions from factories and cars. Acid rain looks just like 'normal' rain but when it falls, it can hurt plants and animals. For example, when acid rain falls into a lake or river, it makes that body of water more acidic. Many plants and animals cannot live in acidic water. Play this game, from Earth Day Canada's EcoKids program, to learn more about acid rain and its impact on the environment.
Antimicrobial activity of some ricinoleic acid oleic acid derivatives
Arthur F. Novak; Gladys C. Clark; Harold P. Dupuy
Ricinoleic and acid oleic acid derivatives were screened for their antimicrobial activity, under optimum growing-conditions,\\u000a against several species of bacteria, yeasts, and molds. Several ricinoleic acid derivatives and petroselinic (iso-oleic) acid\\u000a exhibited considerable activity; in fact, their activity against some micro-organisms was comparable to sorbic and 10-undecenoic\\u000a acid, known antimicrobial agents, as indicated by this test.
Composition for nucleic acid sequencing
Jonas Korlach; Watt W. Webb; Michael Levene; Stephen Turner; Harold G. Craighead; Mathieu Foquet
The present invention is directed to a method of sequencing a target nucleic acid molecule having a plurality of bases. In its principle, the temporal order of base additions during the polymerization reaction is measured on a molecule of nucleic acid, i.e. the activity of a nucleic acid polymerizing enzyme on the template nucleic acid molecule to be sequenced is
Ursodeoxycholic acid, 7-ketolithocholic acid, and chenodeoxycholic acid are primary bile acids of the nutria (Myocastor coypus).
Tint, G S; Bullock, J; Batta, A K; Shefer, S; Salen, G
Because ursodeoxycholic and chenodeoxycholic acids are interconverted in humans via 7-ketolithocholic acid, bile acid metabolism was studied in the nutria (Myocastor coypus), the bile of which is known to contain these three bile acids. Relative concentrations of ursodeoxycholic (37% +/- 20%), 7-ketolithocholic (33% +/- 17%), and chenodeoxycholic (17% +/- 9%) acids in gallbladder bile were unchanged by 5-20 h of complete biliary diversion (n = 7). Injection of either [14C]cholesterol, [14C]ursodeoxycholic, [14C]7-ketolithocholic acid, or a mixture of [7 beta-3H]chenodeoxycholic acid and [14C]chenodeoxycholic acid into bile fistula nutria demonstrated that all three bile acids can be synthesized hepatically from cholesterol, that they are interconverted sparingly (2%-5%) by the liver, but that 7-ketolithocholic acid is an intermediate in the hepatic transformation of chenodeoxycholic acid to ursodeoxycholic acid. An animal that had been fed antibiotics showed an unusually elevated concentration of ursodeoxycholic acid in gallbladder and hepatic bile, suggesting that bacterial transformation of ursodeoxycholic acid in the intestine may be a source of some biliary chenodeoxycholic acid and 7-ketolithocholic acid. PMID:3943698
Acid Catalysis in Modern Organic
Snyder, Scott A.
Acid Catalysis in Modern Organic Synthesis "Acid is one of the oldest, but the most important follows their earlier book "Lewis Acids in Organic Synthesis (2000)", and covers the new developments of university studies, in which an evil-smelling carbox- ylic acid and an alcohol were converted into a fragrant
Molecular Structure of Malonic acid
NSDL National Science Digital Library
Propanedioic acid is a dibasic carboxylic acid that was first synthesized by oxidizing malic acid in 1858 by a scientist named Dessaigne. Naturally, propandioic acid is found in apples. This chemical is relatively unstable and has few uses, but its ester derivative, diethyl malonate, is used to synthesize useful compounds such as barbiturates, flavors, fragrances, and vitamins (B1 and B6).
Atmospheric Dust and Acid Rain
Lars O. Hedin; Gene E. Likens
Why is acid rain still an environmental problem in Europe and North America despite antipollution reforms? The answer really is blowing in the wind: atmospheric dust. These airborne particles can help neutralize the acids falling on forests, but dust levels are unusually low these days. In the air dust particles can neutralize acid rain. What can we do about acid
Corrosion inhibitors used in acidizing
Cizek, A. (Baker Performance Chemicals Inc., Houston, TX (United States). Aquaness Chemical Division)
The history of the development of oil well acidizing and acid corrosion inhibitors used by this industry is reviewed. As deeper and hotter wells were drilled, stimulation acids were exposed to hotter conditions and the organic inhibitors required intensifiers. High-temperature acid corrosion inhibitors are also discussed.
Triterpenic acids in table olives
Concepción Romero; Aranzazu García; Eduardo Medina; Antonio de Castro; Manuel Brenes
An experimental investigation was carried out for the first time on the triterpenic acids in table olives. Maslinic acid was found in a higher concentration than oleanolic acid in the flesh of 17, unprocessed olive varieties, with the Picual and the Manzanilla varieties showing the highest and almost the lowest contents, respectively. The level of triterpenic acids in several types
Pelargonic acid weed control parameters
Technology Transfer Automated Retrieval System (TEKTRAN)
Producers and researchers are interested in pelargonic acid (nonanoic acid) as a broad-spectrum post-emergence or burn-down herbicide. Pelargonic acid is a fatty acid naturally occurring in many plants and animals, and present in many foods we consume. The objective of this research was to determine...
Molecular Structure of Succinic acid
NSDL National Science Digital Library
Succinic acid is an odorless and colorless crystal, triclinic or monoclinic prism with a very acid taste. Succinic acid is one of the natural acids found in broccoli, rhubarb, beets, asparagus, fresh meat extracts, sauerkraut and cheese. It is also a constituent of almost all plant and animal tissues and plays an important role in intermediary metabolism. Succinic acid is produced commercially by catalytic hydrogenation of maleic or fumaric acid or by acid hydrolysis of succinonitrile. Succinic acid is used in flavoring for food and beverages, and in the manufacture of lacquers, dyes, esters for perfumes, succinates, in photography and in foods as a sequestrant, buffer and neutralizing agent. Succinic acid has uses in certain drug compounds and in agricultural production. An interesting fact, succcinic acid has also been found in meteorites.
A Direct, Biomass-Based Synthesis of Benzoic Acid: Formic Acid-Mediated Deoxygenation of the Glucose-Derived Materials Quinic Acid and Shikimic Acid
Arceo, Elena; Ellman, Jonathan; Bergman, Robert
An alternative biomass-based route to benzoic acid from the renewable starting materials quinic acid and shikimic acid is described. Benzoic acid is obtained selectively using a highly efficient, one-step formic acid-mediated deoxygenation method.
Asphaltene damage in matrix acidizing
Hinojosa, Roberto Antonio
REVIEW CONSTRUCTION OF APPARATUS . DESCRIPTION OF CORE SAMPLES DESIGN OF EXPERIMENTAL ACID TREATMENT . . . ACIDIZING RESULTS BRINE SATURATED CORE L1D ACIDIZING RESULTS BRINE/CRUDE OIL SATURATED CORE S2A . . . ACIDIZING RESULTS BRINE/KEROSENE OIL... experiment they used HCl saturated kerosene to test the same crude samples. Deposition occurred with the HCl saturated acid. The authors concluded, though deposition at an interface was preferential, sludge formation did not require an interface. Moore et...
Molecular Structure of Citric Acid
NSDL National Science Digital Library
Citric Acid was first isolated in 1734 by Carl Wilhelm Scheele. Citric acid is found in many fruits, in particular lemons, grapefruit, and oranges. Several types of bacteria and fungi are also known to produce citric acid. In fact, the fungus Aspergillus niger produces the vast majority of citric acid, which is used in almost all carbonated sodas. Additionally, citric acid is also used to clean stainless steel.
Science Shorts: Understanding Acid Rain
NSDL National Science Digital Library
Kathleen Damonte
You may have heard acid rain mentioned as an environmental problem. It doesn't mean that a strong chemical is raining from the sky. The term acid rain describes rain, snow, or fog that is more acidic than normal precipitation. However, a small change in how acidic precipitation is can have a profound effect. This month's activity will help students understand the effect of acid rain on buildings and statues.
Jorgensen, Betty S. (Jemez Springs, NM); Nekimken, Howard L. (Los Alamos, NM); Carey, W. Patrick (Lynnwood, WA); O'Rourke, Patrick E. (Martinez, GA)
An apparatus and method for determining acid concentrations in solutions having acid concentrations of from about 0.1 Molar to about 16 Molar is disclosed. The apparatus includes a chamber for interrogation of the sample solution, a fiber optic light source for passing light transversely through the chamber, a fiber optic collector for receiving the collimated light after transmission through the chamber, a coating of an acid resistant polymeric composition upon at least one fiber end or lens, the polymeric composition in contact with the sample solution within the chamber and having a detectable response to acid concentrations within the range of from about 0.1 Molar to about 16 Molar, a measurer for the response of the polymeric composition in contact with the sample solution, and, a comparer of the measured response to predetermined standards whereby the acid molarity of the sample solution within the chamber can be determined. Preferably, a first lens is attached to the end of the fiber optic light source, the first lens adapted to collimate light from the fiber optic light source, and a second lens is attached to the end of the fiber optic collector for focusing the collimated light after transmission through the chamber.
Acid neutralizing capacity, alkalinity, and acid-base status of natural waters containing organic acids
Harold F. Hemond
The terms acid neutralizing capacity (ANC) and alkalinity (Alk) are extensively employed in the characterization of natural waters, including soft circumneutral or acidic waters. However, in the presence of organic acids, ANC measurements are inconsistent with many conceptual definitions of ANC or Alk and do not provide an adequate characterization of the acid-base chemistry of water. Knowledge of Gran ANC
The Acid-Base Titration of a Very Weak Acid: Boric Acid
ERIC Educational Resources Information Center
Celeste, M.; Azevedo, C.; Cavaleiro, Ana M. V.
A laboratory experiment based on the titration of boric acid with strong base in the presence of d-mannitol is described. Boric acid is a very weak acid and direct titration with NaOH is not possible. An auxiliary reagent that contributes to the release of protons in a known stoichiometry facilitates the acid-base titration. Students obtain the…
40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.
Code of Federal Regulations, 2012 CFR
...acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 ...acid amine condensate, polycarboxylic acid salts. (a) Chemical substance and significant...acid amine condensate, polycarboxylic acid salts. (PMN P-92-445) is subject...
Balogun, Mohammed O; Huws, Enlli H; Sirhan, Muthana M; Saleh, Ahmed D; Al Dulayymi, Juma'a R; Pilcher, Lynne; Verschoor, Jan A; Baird, Mark S
Patient serum antibodies to mycolic acids have the potential to be surrogate markers of active tuberculosis (TB) when they can be distinguished from the ubiquitously present cross-reactive antibodies to cholesterol. Mycolic acids are known to interact more strongly with antibodies present in the serum of patients with active TB than in patients with latent TB or no TB. Examples of single stereoisomers of mycolic acids with chain lengths corresponding to major homologues of those present in Mycobacterium tuberculosis have now been synthesised with a sulfur substituent on the terminal position of the ?-chain; initial studies have established that one of these binds to a gold electrode surface, offering the potential to develop second generation sensors for diagnostic patient antibody detection. PMID:23603063
Bioavailability of ferulic acid.
Bourne, L C; Rice-Evans, C
There is a wealth of evidence for the powerful antioxidant properties in vitro of flavonoid components of the diet. However, few studies have been undertaken concerning the hydroxycinnamates, major constituents of fruit, some vegetables, beverages, and grains, particularly the extent to which they are absorbed in vivo from the diet. The study described here has investigated the bioavailability of ferulic acid in humans, from tomato consumption, through the monitoring of the pharmacokinetics of excretion in relation to intake. The results show that the peak time for maximal urinary excretion is approximately 7 h and the recovery of ferulic acid in the urine, on the basis of total free ferulic acid and feruloyl glucuronide excreted, is 11-25% of that ingested. PMID:9878519
Oleanolic acid ethanol monosolvate
Froelich, Anna; Gzella, Andrzej K.
Crystals of the title compound (systematic name: 3?-hydroxyolean-12-en-28-oic acid ethanol monosolvate), C30H48O3·C2H5OH, were obtained from unsuccessful co-crystallization trials. The asymmetric unit contains two symmetry-independent oleanolic acid molecules, as well as two ethanol solvent molecules. Intermolecular O—H?O hydrogen bonds stabilize the crystal packing. In the oleanolic acid molecules, ring C has a slightly distorted envelope conformation, while rings A, B, D and E adopt chair conformations and rings D and E are cis-fused. Both independent ethanol molecules are orientationally disordered [occupancy ratios of 0.742?(8):0.258?(8) and 0.632?(12):0.368?(12). PMID:21588987
[Studies on interaction of acid-treated nanotube titanic acid and amino acids].
Zhang, Huqin; Chen, Xuemei; Jin, Zhensheng; Liao, Guangxi; Wu, Xiaoming; Du, Jianqiang; Cao, Xiang
Nanotube titanic acid (NTA) has distinct optical and electrical character, and has photocatalysis character. In accordance with these qualities, NTA was treated with acid so as to enhance its surface activity. Surface structures and surface groups of acid-treated NTA were characterized and analyzed by Transmission Electron Microscope (TEM) and Fourier Transform Infrared Spectrometry (FT-IR). The interaction between acid-treated NTA and amino acids was investigated. Analysis results showed that the lengths of acid-treated NTA became obviously shorter. The diameters of nanotube bundles did not change obviously with acid-treating. Meanwhile, the surface of acid-treated NTA was cross-linked with carboxyl or esterfunction. In addition, acid-treated NTA can catch amino acid residues easily, and then form close combination. PMID:20649031
NASA Astrophysics Data System (ADS)
Bhatti, Neeloo; Streets, David G.; Foell, Wesley K.
Acid rain has been an issue of great concern in North America and Europe during the past several decades. However, due to the passage of a number of recent regulations, most notably the Clean Air Act in the United States in 1990, there is an emerging perception that the problem in these Western nations is nearing solution. The situation in the developing world, particularly in Asia, is much bleaker. Given the policies of many Asian nations to achieve levels of development comparable with the industrialized world—which necessitate a significant expansion of energy consumption (most derived from indigenous coal reserves)—the potential for the formation of, and damage from, acid deposition in these developing countries is very high. This article delineates and assesses the emissions patterns, meteorology, physical geology, and biological and cultural resources present in various Asian nations. Based on this analysis and the risk factors to acidification, it is concluded that a number of areas in Asia are currently vulnerable to acid rain. These regions include Japan, North and South Korea, southern China, and the mountainous portions of Southeast Asia and southwestern India. Furthermore, with accelerated development (and its attendant increase in energy use and production of emissions of acid deposition precursors) in many nations of Asia, it is likely that other regions will also be affected by acidification in the near future. Based on the results of this overview, it is clear that acid deposition has significant potential to impact the Asian region. However, empirical evidence is urgently needed to confirm this and to provide early warning of increases in the magnitude and spread of acid deposition and its effects throughout this part of the world.
Ethylenediaminetetraacetic acid in endodontics
Mohammadi, Zahed; Shalavi, Sousan; Jafarzadeh, Hamid
Ethylenediaminetetraacetic acid (EDTA) is a chelating agent can bind to metals via four carboxylate and two amine groups. It is a polyamino carboxylic acid and a colorless, water-soluble solid, which is widely used to dissolve lime scale. It is produced as several salts, notably disodium EDTA and calcium disodium EDTA. EDTA reacts with the calcium ions in dentine and forms soluble calcium chelates. A review of the literature and a discussion of the different indications and considerations for its usage are presented. PMID:24966721
NSDL National Science Digital Library
In this activity students will design an apparatus and carry out tests of fossil fuels to determine their impact on acid deposition by placing a small amount of a fossil fuel on a cotton puff and burning it to measure if acidic compounds are given off. Students will provide a diagram of their collection device and describe how it should function. Students will then draw a map showing the location of their precipitation collector and develop a graph or chart based on the results they have collected.
Lactic acid bacterial cell factories for gamma-aminobutyric acid
Haixing Li; Yusheng Cao
Gamma-aminobutyric acid is a non-protein amino acid that is widely present in organisms. Several important physiological functions\\u000a of gamma-aminobutyric acid have been characterized, such as neurotransmission, induction of hypotension, diuretic effects,\\u000a and tranquilizer effects. Many microorganisms can produce gamma-aminobutyric acid including bacteria, fungi and yeasts. Among\\u000a them, gamma-aminobutyric acid-producing lactic acid bacteria have been a focus of research in recent
Synthesis of acid addition salt of delta-aminolevulinic acid from 5-bromo levulinic acid esters
Moens, Luc (Lakewood, CO)
A process of preparing an acid addition salt of delta-aminolevulinc acid comprising: a) dissolving a lower alkyl 5-bromolevulinate and hexamethylenetetramine in a solvent selected from the group consisting of water, ethyl acetate, chloroform, acetone, ethanol, tetrahydrofuran and acetonitrile, to form a quaternary ammonium salt of the lower alkyl 5-bromolevulinate; and b) hydrolyzing the quaternary ammonium salt with an inorganic acid to form an acid addition salt of delta-aminolevulinic acid.
Molecular Structure of Aspartic Acid
NSDL National Science Digital Library
Aspartate was first isolated in 1868 from legumin in plant seeds. Aspartic acid forms colorless crystals that are soluble in water and insoluble in alcohols and ethers. This is a naturally occurring nonessential amino acid that is produced in the liver from oxaloacetic acid, but is plentiful in meats and sprouting seeds. The amino acid is important in the Krebs cycle as well as the urea cycle, where it is vital in the elimination of dietary waste products. Aspartic acid is required for stamina, brain and neural health. This acid has been found to be important in the functioning of ribonucleic acid (RNA), deoxyribonucleic acid (DNA), and in the production of immunoglobin and antibody synthesis. A deficiency of aspartate will lead to fatigue and depression. Aspartic acid has many uses that include biological and clinical studies, preparation of culture media, and it also functions as a detergent, fungicide, germicide, and metal complexation.
Thin layer chromatography of p-aminophenol in urine after mixed exposure to aniline and toluene.
Bieniek, G; Karma?ska, K; Wilczok, T
A simple method of evaluating p-aminophenol in the urine of people exposed simultaneously to aniline and toluene relies on separating p-aminophenol from hippuric acid and other physiological components of the urine by thin layer chromatography. The adsorbents and developing system have been thus fixed to make possible the separation of p-aminophenol from hippuric acid, urea, and creatinine and their quantitative determination. This method also makes possible the determination of p-aminophenol in urine in the presence of hippuric acid. Hippuric acid is a physiological component of urine and also the metabolite of toluene, so the determination of p-aminophenol is possible also after simultaneous exposure to both compounds: aniline and toluene. At the same time the concentrations of urea and creatinine as additional factors may be determined. The limit of detection of the method is: 5 micrograms/ml for p-aminophenol, 9 micrograms/ml for hippuric acid, 8 micrograms/ml for urea, and 6 micrograms/ml for creatinine. PMID:6722055
Sven Darling
IT has previously been reported by Cohen1 that enzyme preparations catalysing the reactions : (1) Alanine + alpha-ketoglutarate rlharr glutamate + pyruvate; (2) Aspartate + alpha-ketoglutarate rlharr glutamate + oxalo acetate; are also capable of catalysing : (3) Cysteic acid + alpha-ketoglutarate rlharr glutamate + sulphopyruvate. (In a succeeding paper it will be shown that reaction (3) is reversible, which
Microbial hyaluronic acid production
Barrie Fong Chong; Lars M. Blank; Richard Mclaughlin; Lars K. Nielsen
sHyaluronic acid (HA) is a commercially valuable medical biopolymer increasingly produced through microbial fermentation. Viscosity limits product yield and the focus of research and development has been on improving the key quality parameters, purity and molecular weight. Traditional strain and process optimisation has yielded significant improvements, but appears to have reached a limit. Metabolic engineering is providing new opportunities and
Spermatotoxicity of dichloroacetic acid
The testicular toxicity of dichloroacetic acid (DCA), a disinfection byproduct of drinking water, was evaluated in adult male rats given both single and multiple (up to 14 d) oral doses. Delayed spermiation and altered resorption of residual bodies were observed in rats given sin...
Martin Rostami Yazdi; Ulrich Mrowietz
Several clinical studies have shown that systemic therapy with fumaric acid esters (FAEs) in patients with moderate to severe psoriasis is effective and has a good long-term safety profile. For therapeutic use, tablets with a defined mixture of FAEs (dimethylfumarate [DMF] and three different salts of monoethylfumarate) are registered in Germany. There is evidence that DMF is the most essential
This report documents the discussion and results of the U.S. EPA Acid Aerosol Measurement Workshop, conducted February 1-3, 1989, in Research Triangle Park, North Carolina. t was held in response to recommendations by the Clean Air Scientific Advisory Committee (CASAC) regarding ...
ERIC Educational Resources Information Center
Rakow, Steven J.; Glenn, Allen
Provides rationale for and description of an acid rain game (designed for two players), a problem-solving model for elementary students. Although complete instructions are provided, including a copy of the game board, the game is also available for Apple II microcomputers. Information for the computer program is available from the author.…
ERIC Educational Resources Information Center
Hugo, John C.
Presents an activity in which students investigate the formation of solid ammonium chloride aerosol particles to help students better understand the concept of acid rain. Provides activity objectives, procedures, sample data, clean-up instructions, and questions and answers to help interpret the data. (MDH)
Sayers, C.S.
This bibliography identifies 900 citations on various aspects of Acid Rain, covering published bibliographies, books, reports, conference and symposium proceedings, audio visual materials, pamphlets and newsletters. It includes five sections: citations index (complete record of author, title, source, order number); KWIC index; title index; author index; and source index. 900 references.
Arthur J. Caplan; Emilson C. D. Silva
Federal environmental policy, designed to control acid rain, is shaped after the hierarchy of the system, and is controlled simultaneously by regional and central governments. Each governmental level controls one of two policy instruments: pollution abatement production and pollution tax. In a two-stage game where regional governments are Stackelberg leaders and control pollution taxes, the subgame perfect equilibrium is socially
NSDL National Science Digital Library
This portal provides links to information on the potential damage caused to the environment by acid rain. An introductory paragraph briefly describes the damage to lakes and streams, building materials, and monuments. Each link access additional information on these topics: surface waters and aquatic animals, forests, automotive coatings, soluble building materials such as marble or limestone, atmospheric haze, and human health effects.
ERIC Educational Resources Information Center
Demchik, Michael J.
Describes a curriculum plan in which students learn about acid rain through instructional media, research and class presentations, lab activities, simulations, design, and design implementation. Describes the simulation activity in detail and includes materials, procedures, instructions, examples, results, and discussion sections. (SAH)
ERIC Educational Resources Information Center
Bybee, Rodger; And Others
Describes an activity which provides opportunities for role-playing as industrialists, ecologists, and government officials. The activity involves forming an international commission on acid rain, taking testimony, and, based on the testimony, making recommendations to governments on specific ways to solve the problem. Includes suggestions for…
ERIC Educational Resources Information Center
Oates-Bockenstedt, Catherine
Details an activity designed to motivate students by incorporating science-related issues into a classroom debate. Includes "The Acid Rain Bill" and "Position Guides" for student roles as committee members, consumers, governors, industry owners, tourism professionals, senators, and debate directors. (DKM)
S. A. Norton
Air pollution by acids has been known as a problem for centuries (Ducros, 1845; Smith, 1872; Camuffo, 1992; Brimblecombe, 1992). Only in the mid-1900s did it become clear that it was a problem for more than just industrially developed areas, and that precipitation quality can affect aquatic resources ( Gorham, 1955). The last three decades of the twentieth century saw
Acid Mine Drainage Remediation
NSDL National Science Digital Library
In this video, an environmental technologist visits an abandoned coal mine in Kentucky to talk about how a remediation system (a series of settling ponds and treatment cells) is neutralizing the acid drainage flowing from the mine and keeping it from damaging a creek downstream.
ERIC Educational Resources Information Center
Stubbs, Harriett S.
Presented is a science activity designed to help students monitor the pH of rainfall. Materials, procedures and follow-up activities are listed. A list of domestic and foreign sources of information is provided. Topics which relate to acid precipitation are outlined. (CW)
Pfleger, Brian F; Lennen, Rebecca M
Described are hosts for overproducing a fatty acid product such as a fatty acid. The hosts include an exogenous nucleic acid encoding a thioesterase and, optionally, an exogenous nucleic acid encoding an acetyl-CoA carboxylase, wherein an acyl-CoA synthetase in the hosts are functionally delected. The hosts prefereably include the nucleic acid encoding the thioesterase at an intermediate copy number. The hosts are preferably recominantly stable and growth-competent at 37.degree. C. Methods of producing a fatty acid product comprising culturing such hosts at 37.degree. C. are also described.
Inhibition of oxidative degradation of hyaluronic acid by uric acid.
Liu, K M; Swann, D; Lee, P; Lam, K W
It has been postulated that glycosaminoglycans in the trabeculum have an influence on aqueous humor drainage. Ascorbate reduces the viscosity of hyaluronic acid, and also increases outflow facility. Our recent observation of high urate concentrations in some glaucomatous eyes led us to study the influence of urate on oxidative degradation of hyaluronic acid by ascorbate. The viscosity of rooster comb hyaluronic acid was reduced slowly by ascorbate. Cupric sulfate accelerated ascorbate oxidation and also enhanced hyaluronic acid degradation. Urate inhibited ascorbate oxidation and prevented the copper catalyzed oxidative degradation of rooster comb hyaluronic acid. The range of urate concentrations used in this study was within the range of urate concentrations observed in glaucomatous eyes. The partially purified umbilical cord hyaluronic acid had lower viscosity than rooster comb hyaluronic acid, and rapidly degraded in the presence of ascorbate. The ascorbate effect on umbilical cord hyaluronic acid was partially prevented by urate. PMID:6488856
Photostabilization of ascorbic acid with citric acid, tartaric acid and boric acid in cream formulations.
Ahmad, I; Ali Sheraz, M; Ahmed, S; Shad, Z; Vaid, F H M
This study involves the evaluation of the effect of certain stabilizers, that is, citric acid (CT), tartaric acid (TA) and boric acid (BA) on the degradation of ascorbic acid (AH(2) ) in oil-in-water cream formulations exposed to the UV light and stored in the dark. The apparent first-order rate constants (0.34-0.95 × 10(-3) min(-1) in light, 0.38-1.24 × 10(-2) day(-1) in dark) for the degradation reactions in the presence of the stabilizers have been determined. These rate constants have been used to derive the second-order rate constants (0.26-1.45 × 10(-2) M(-1) min(-1) in light, 3.75-8.50 × 10(-3) M(-1) day(-1) in dark) for the interaction of AH(2) and the individual stabilizers. These stabilizers are effective in causing the inhibition of the rate of degradation of AH(2) both in the light and in the dark. The inhibitory effect of the stabilizers is in the order of CT > TA > BA. The rate of degradation of AH(2) in the presence of these stabilizers in the light is about 120 times higher than that in the dark. This could be explained on the basis of the deactivation of AH(2) -excited triplet state by CT and TA and by the inhibition of AH(2) degradation through complex formation with BA. AH(2) leads to the formation of dehydroascorbic acid (A) by chemical and photooxidation in cream formulations. PMID:22296174
Recovery of Carboxylic Acids from Fermentation Broth via Acid Springing
Dong, Jipeng
RECOVERY OF CARBOXYLIC ACIDS FROM FERMENTATION BROTH VIA ACID SPRINGING A Thesis by JIPENG DONG Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 2008 Major Subject: Chemical Engineering RECOVERY OF CARBOXYLIC ACIDS FROM FERMENTATION BROTH VIA ACID SPRINGING A Thesis by JIPENG DONG Submitted to the Office of Graduate Studies of Texas A...
Fatty acid selectivity of lipases: Erucic acid from rapeseed oil
Philip E. Sonnet; Thomas A. Foglia; Stephen H. Feairheller
The fatty acid selectivity of several commercial lipases was evaluated in the hydrolysis of high-erucic acid rapeseed oil\\u000a (HEARO). The lipase ofPseudomonas cepacia catalyzed virtually complete hydrolysis of the oil (94–97%), while that ofGeotrichum candidum discriminated strongly against erucic acid, especially in esterification. A two-step process is suggested for obtaining a\\u000a highly enriched erucic acid in which theG. candidum lipase
Thiobarbituric Acid Spray Reagent for Deoxy Sugars and Sialic Acids
Leonard Warren
RECENTLY, new sensitive assays have been reported for deoxy sugars1, 2-keto,3-deoxy sugar acids2-4, and sialic acids5,6. In these assays, the products of periodate oxidation, malonaldehyde from deoxy sugars and beta-formylpyruvic acid from the latter two groups of compounds, are coupled with 2-thiobarbituric acid to produce a bright red chromophore. I wish to report an adaptation of these methods for spraying
Dietary omega-3 fatty acids for women
Jean-Marie Bourre
This review details the specific needs of women for omega-3 fatty acids, including alpha linoleic acid (ALA) and the very long chain fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Omega-3 fatty acid (dietary or in capsules) ensures that a woman's adipose tissue contains a reserve of these fatty acids for the developing fetus and the breast-fed newborn infant.
Acid placement and coverage in the acid jetting process
Mikhailov, Miroslav I.
Many open-hole acid treatments are being conducted by pumping acid through jetting ports placed at the end of coiled tubing or drill pipe. The filter-cake on the bore-hole is broken by the jet; the acid-soluble material is dissolved, creating...
Acid Placement in Acid Jetting Treatments in Long Horizontal Wells
Sasongko, Hari
In the Middle East, extended reach horizontal wells (on the order of 25,000 feet of horizontal displacement) are commonly acid stimulated by jetting acid out of drill pipe. The acid is jetted onto the face of the openhole wellbore as the drill pipe...
Technology Transfer Automated Retrieval System (TEKTRAN)
Hypochlorite reacted with kojic acid to form an intensely fluorescent product with excitation and emission wavelengths at 395 and 495 nm, respectively. Hypobromite, generated by reaction of hypochlorite or peroxyacetic acid with NaBr, also reacted with kojic acid to generate an identical fluorescen...
College Chemistry Students' Mental Models of Acids and Acid Strength
ERIC Educational Resources Information Center
McClary, LaKeisha; Talanquer, Vicente
The central goal of this study was to characterize the mental models of acids and acid strength expressed by advanced college chemistry students when engaged in prediction, explanation, and justification tasks that asked them to rank chemical compounds based on their relative acid strength. For that purpose we completed a qualitative research…
Acid adaptation sensitizes Salmonella typhimurium to hypochlorous acid.
Leyer, G J; Johnson, E A
Acid adaptation of Salmonella typhimurium at a pH of 5.0 to 5.8 for one to two cell doublings resulted in marked sensitization of the pathogen to halogen-based sanitizers including chlorine (hypochlorous acid) and iodine. Acid-adapted S. typhimurium was more resistant to an anionic acid sanitizer than was its nonadapted counterpart. A nonselective plating medium of tryptose phosphate agar plus 1% pyruvate was used throughout the study to help recover chemically stressed cells. Mechanisms of HOCl-mediated inactivation of acid-adapted and nonadapted salmonellae were investigated. Hypochlorous acid oxidized a higher percentage of cell surface sulfhydryl groups in acid-adapted cells than in nonadapted cells, and sulfhydryl oxidation was correlated with cell inactivation. HOCl caused severe metabolic disruptions in acid-adapted and nonadapted S. typhimurium, such as respiratory loss and inability to restore the adenylate energy charge from a nutrient-starved state. Sensitization of S. typhimurium to hypochlorous acid by acid adaptation also involved increased permeability of the cell surface because nonadapted cells treated with EDTA became sensitized. The results of this study establish that acid-adapted S. typhimurium cells are highly sensitized to HOCl oxidation and that inactivation by HOCl involves changes in membrane permeability, inability to maintain or restore energy charge, and probably oxidation of essential cellular components. This study provides a basis for improved practical technologies to inactivate Salmonella and implies that acid pretreatment of food plant environments may increase the efficacy of halogen sanitizers. PMID:9023924
Focus Sheet | Hydrofluoric Acid Health hazards of hydrofluoric acid
Wilcock, William
Focus Sheet | Hydrofluoric Acid Health hazards of hydrofluoric acid Hydrofluoric acid (HF eye damage. HF vapors can seriously damage the lungs. Pulmonary edema (flooding of the lungs characterized by weight loss, brittle bones, anemia, and general ill health. Safe use If possible, avoid working
Pantothenic acid is a vitamin, also known as vitamin B5. It is widely found in both plants and animals ... Vitamin B5 is commercially available as D-pantothenic acid, as well as dexpanthenol and calcium pantothenate, which ...
Molecular Structure of Glutaric acid
NSDL National Science Digital Library
Glutaric acid is a colorless liquid and white crystals as a solid occurring in plants and animal tissues. It is used in organic synthesis and as an intermediate for the manufacture of polymers such as polyamides and polyesters, ester plasticizers and corrosion inhibitors. It is also useful in the application of decreasing polymer elasticity and in a variety of industrial applications. In addition glutaric acid plays an important role as an intermediary in the Krebs cycle and is used in medication against a large number of viruses and in animal diabetes. Glutaric acid can be prepared from cyclopentanone by oxidative ring fission with nitric acid and in the presence of a catalyst. Glutaric acid has the lowest melting point among dicarboxylic acids (98 C); it is very soluble in water and the solution in water is a medium strong acid. Short-term exposure to glutaric acid may cause irritation to the eyes, skin and the respiratory tract.
Molecular Structure of Maleic acid
NSDL National Science Digital Library
Maleic acid is colorless to white crystals with a faint acidulous odor and a characteristic repulsive, astringent taste. Maleic acid is used in making polyesters, surface coatings, lubricant additives, agricultural chemicals and paint vehicles. It is used in organic synthesis of fumaric acid, succinic, aspartic, tartaric, propionic, lactic, malonic, acrylic and hydrocarylic acids. Maleic acid and its anhydride are prepared industrially by the catalytic oxidation of benzene. Maleic acid may be released into waste water during its production and used in the manufacture of polymer products. Dust of maleic acid is irritating to the eyes, nose and throat. The general population is exposed to maleic acid in areas with heavy traffic since it is found in aerosols from auto exhaust.
Uranium (VI) - Chromotropic Acid Chelate
Samir K. Banerji; Arun K. Dey
DISODIUM- 1:8-dihydroxy naphthalene-3:6-disulphonate (trivial name chromotropic acid-sodium salt)yields coloured lakes with various cations1. Investigations of chelates of chromotropic acid with iron (III)2 and titanium (IV)3,4 have already been made. Sommer et al. have extensively examined chelates of titanium with chromotropic acid and various polyphenols5-7 and have discussed the structure of the metal chelates. The use of chromotropic acid in the
Fatty acid signaling in Arabidopsis
Edward E. Farmer; Hans Weber; Sabine Vollenweider
. Many organisms use fatty acid derivatives as biological regulators. In plants, for example, fatty acid-derived signals have\\u000a established roles in the regulation of developmental and defense gene expression. Growing numbers of these compounds, mostly\\u000a derived from fatty acid hydroperoxides, are being characterized. The model plant Arabidopsis thaliana is serving a vital role in the discovery of fatty acid-derived signal
Molecular Structure of Trimesic acid
NSDL National Science Digital Library
Trimesic Acid is made up of a benzene ring with three carboxylic groups at the 1, 3, and 5 positions, and it can be synthesized from the oxidation of 1,3,5-trimethyl benzene. The acid is an important building block in crystal engineering which is used to form honeycomb structures, but it has the ability to form diverse supramolecular structures. Also, trimesic acid salt and the free trimesic acid are useful as a plasticizer.
Molecular Structure of Acetic acid
NSDL National Science Digital Library
Acetic Acid commonly associated with vinegar; it is the most commercially important organic acid and is used to manufacture a wide range of chemical products, such as plastics and insecticides. Acetic acid is produced naturally by Aceto bacteria but, except for making vinegar, is usually made through synthetic processes. Ethanoic acid is used as herbicide, as a micro-biocide, as a fungicide and for pH adjustment.
Molecular Structure of Octanoic acid
NSDL National Science Digital Library
Caprylic acid is a colorless oil manufactured from 1-heptene or 1-octanol. Octanoic acid has an unpleasant rancid taste. When converted from the carboxlic acid to an ester, it has a pleasant taste. In addition, esters of caprylic acid are used in the preparation of dyes, perfumes, and food preservatives. This compound has also been found to have antifungal activity and is used to treat yeast infections.
Acid rain: Reign of controversy
Kahan, A.M.
Acid Rain is a primer on the science and politics of acid rain. Several introductory chapters describe in simple terms the relevant principles of water chemistry, soil chemistry, and plant physiology and discuss the demonstrated or postulated effects of acid rain on fresh waters and forests as well as on statuary and other exposed objects. There follow discussions on the economic and social implications of acid rain (for example, possible health effects) and on the sources, transport, and distribution of air pollutants.
Enviropedia: Introduction to Acid Rain
NSDL National Science Digital Library
This resource provides information about acid rain, a widespread term used to describe all forms of acid precipitation. The sources, nature, and chemistry of acid rain are discussed, along with its impact on buildings, soils, freshwater lakes, trees, and wildlife. Other topics include measuring, modeling, and monitoring acid rain; and vehicle and industrial emission controls. The problem of airborne pollutants migrating across international borders is also discussed.
Factors Controlling Naphthenic Acid Corrosion
Alan Turnbull; Evelina Slavcheva; Bryan Shone
A laboratory study was conducted to elucidate the influence of chemical and physical parameters on corrosion of type 1018 carbon steel (CS, UNS G10180) and 5% Cr-0.5% Mo steel in oils containing naphthenic acids (NAs) for application to crude oil refinery systems. Effects of test duration, temperature, and acid concentration were assessed for a range of single acids of varying
Nucleic Acids Molecular Biology Tools
Qiu, Weigang
Nucleic Acids Proteins Molecular Biology Tools Molecular Biology and Genomics Weigang Qiu Weigang Qiu Molecular Biology and Genomics #12;Nucleic Acids Proteins Molecular Biology Tools Outline 1 Nucleic Acids 2 Proteins 3 Molecular Biology Tools Weigang Qiu Molecular Biology and Genomics #12;Nucleic
CHARACTERISTICS Picric acid is a
Wilcock, William
CHARACTERISTICS · Picric acid is a trinitroaromatic compound that is a flammable solid when purchased wet with 30% water, by mass. · Picric acid is a high-powered explosive when allowed to dehydrate. As an explosive, picric acid is not shock sensitive, but when in contact with metals can form shock sensitive
Carboxylic acid sorption regeneration process
King, C.J.; Poole, L.J.
Carboxylic acids are sorbed from aqueous feedstocks into an organic liquid phase or onto a solid adsorbent. The acids are freed from the sorbent phase by treating it with aqueous alkylamine thus forming an alkylammonium carboxylate which is dewatered and decomposed to the desired carboxylic acid and the alkylamine. 10 figs.
Toohey, Darin W.
A ACID RAIN Audrey Gibson ATOC 3500 Thursday, April 29, 2010 #12;CAUSES Natural sources - volcanoes Thursday, April 29, 2010 #12;ON WILDLIFE Acid rain causes acidification of lakes and streams and contributes to damage of trees at high elevations. Acid rain primarily affects sensitive bodies of water
ERIC Educational Resources Information Center
Randal, Judith
The Environmental Protection Agency has awarded several grants to study effects of and possible solutions to the problem of "acid rain"; pollution from atmospheric nitric and sulfuric acids. The research program is administered through North Carolina State University at Raleigh and will focus on biological effects of acid rain. (JMF)
D. Pohl; M. Fox; M. Fried; B. Göke; C. Prinz; H. Mönnikes; G. Rogler; M. Dauer; J. Keller; F. Lippl; I. Schiefke; U. Seidler; H. D. Allescher
Evidence from comparative anatomy and physiology studies indicates that gastric acid secretion developed during the evolution of vertebrates approximately 350 million years ago. The cellular mechanisms that produce gastric acid have been conserved over the millennia and therefore proton pump inhibitors have pharmacological effects in almost all relevant species. These observations suggest that gastric acid provides an important selective advantage;
Pantothenic acid biosynthesis in zymomonas
Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V.
Zymomonas is unable to synthesize pantothenic acid and requires this essential vitamin in growth medium. Zymomonas strains transformed with an operon for expression of 2-dehydropantoate reductase and aspartate 1-decarboxylase were able to grow in medium lacking pantothenic acid. These strains may be used for ethanol production without pantothenic acid supplementation in seed culture and fermentation media.
Kobayashi, Yasuo; Arima, Kei
Kobayashi, Yasuo (University of Tokyo, Tokyo, Japan) and Kei Arima. Bacterial oxidation of dipicolinic acid. II. Identification of ?-ketoglutaric acid and 3-hydroxydipicolinic acid and some properties of cell-free extracts. J. Bacteriol. 84:765–771. 1962—When a dipicolinic acid (DPA)-decomposing bacterium, Achromobacter strain 1–2, was incubated at 30 C with shaking in a DPA solution containing 10?3m arsenite, a keto acid was accumulated. The 2,4-dinitrophenylhydrazone of this acid was synthesized and identified as ?-ketoglutaric acid by paper chromatography, visible absorption spectrum, infrared analysis, elemental analysis, and mixed melting point. During this incubation, oxalic acid equivalent to the consumed dipicolinic acid was produced. A fluorescent material was also isolated from culture fluid and identified as 3-hydroxydipicolinic acid by paper chromatography and the ultraviolet absorption spectrum. Further, cell-free extracts were prepared by sonic oscillation. Ferrous ion and a reduced di- or triphosphopyridine nucleotide-generating system were proven to be required for enzymic oxidation of DPA. And 3-hydroxydipicolinic acid was also oxidized by this preparation. From the results obtained, a possible metabolic pathway of dipicolinic acid was proposed. PMID:14033954
NSDL National Science Digital Library
michael stapleton
Students are asked to calculate the pH of a weak acid aqueous solution. The problems involve a series of generic acids with assigned equilibrium constants (Ka) and total concentrations (Ct). Initially, students are required to hand calculate all problems by algebraic manipulation of the mathematical relationships of the system. The solution is a cubic equation. Through a series of assumptions, the solution is simplified. The assumptions are based on the chemistry of the system given the Ka and Ct for the problem. The problems are then graphically solved. Ultimately, the students develop an Excel worksheet to solve the problems and a Bjerrum plot to display the speciation as a function of pH.
Nucleic Acid Detection Methods
Cassandra L. Smith; Ron Yaar; Przemyslaw Szafranski; Charles R. Cantor
The invention relates to methods for rapidly determining the sequence and\\/or length a target sequence. The target sequence may be a series of known or unknown repeat sequences which are hybridized to an array of probes. The hybridized array is digested with a single-strand nuclease and free 3'-hydroxyl groups extended with a nucleic acid polymerase. Nuclease cleaved heteroduplexes can be
Nucleic acid detection methods
C. L. Smith; R. Yaar; P. Szafranski; C. R. Cantor
The invention relates to methods for rapidly determining the sequence and\\/or length a target sequence. The target sequence may be a series of known or unknown repeat sequences which are hybridized to an array of probes. The hybridized array is digested with a single-strand nuclease and free 3â˛-hydroxyl groups extended with a nucleic acid polymerase. Nuclease cleaved heteroduplexes can be
NSDL National Science Digital Library
Learners conduct a simple experiment to model and explore the harmful effects of acid rain (vinegar) on living (green leaf and eggshell) and non-living (paper clip) objects. Learners observe the effects over a period of days. This activity has links to other activities which can be combined to make a larger lesson. Resource contains vocabulary definitions and suggestions for assessment, extensions, and scaling for different levels of learners.
Neeloo Bhatti; David G. Streets; Wesley K. Foell
Acid rain has been an issue of great concern in North America and Europe during the past several decades. However, due to\\u000a the passage of a number of recent regulations, most notably the Clean Air Act in the United States in 1990, there is an emerging\\u000a perception that the problem in these Western nations is nearing solution. The situation in
Turk, Stacey N.
) composition among different depots throughout a beef carcass. To test this, 50 carcasses from a variety of breed types and backgrounds were sampled. External fat samples were collected from eight different carcass locations: round, sirloin, loin, rib... was the lowest. Due to the significant differences amongst fat depots within bovine carcasses in their fatty acid composition we conclude that substantial differences exist across fat depots. v DEDICATION...
Lercker, G; Bocci, F; Frega, N; Bortolomeazzi, R
The cannabinoid pattern of vegetable preparations from Cannabis sativa (hashish, marijuana) allows to recognize the phenotype of the plants, to be used as drug or for fiber. Cannabinoid determination by analytical point of view has represented some problems caused by the complex composition of the hexane extract. Capillary gas chromatography of the hexane extracts of vegetable samples, shows the presence of rather polar constituents that eluted, with noticeable interactions, only on polar phase. The compounds can be methylated by diazomethane and silanized (TMS) by silylating reagents. The methyl and methyl-TMS derivatives are analyzed by high resolution gas chromatography (HRGC) and by gas chromatography-mass spectrometry (GC-MS). The identification of the compounds shows their nature of cannabinoid acids, which the main by quantitative point of view results the cannabidiolic acid (CBDA). It is known that the cannabinoid acids are thermally unstable and are transformed in the corresponding cannabinoids by decarboxilation. This is of interest in forensic analysis with the aim to establish the total amount of THC in the Cannabis preparations, as the active component. PMID:1503600
Degradation of Phthalic Acids and Benzoic Acid from Terephthalic Acid Wastewater by Advanced Oxidation Processes
Ramesh Thiruvenkatachari; Tae Ouk Kwon; Il Shik Moon
Terephthalic acid (TPA) wastewater is traditionally being treated by biological method. This study investigates the degradation of three major toxic target organic species, namely terephthalic acid (TPA), isophthalic acid (IPA), benzoic acid (BA), present in the TPA wastewater, by several advanced oxidation processes. The performance of three main oxidation processes such as photofenton oxidation (UV-H2O2-Fe), photocatalytic ozonation (UV-O3-Fe) and photofenton
Invasive cleavage of nucleic acids
Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)
The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.
Invasive cleavage of nucleic acids
Prudent, James R. (Madison, WI); Hall, Jeff G. (Madison, WI); Lyamichev, Victor I. (Madison, WI); Brow, Mary Ann D. (Madison, WI); Dahlberg, James E. (Madison, WI)
The present invention relates to means for the detection and characterization of nucleic acid sequences, as well as variations in nucleic acid sequences. The present invention also relates to methods for forming a nucleic acid cleavage structure on a target sequence and cleaving the nucleic acid cleavage structure in a site-specific manner. The structure-specific nuclease activity of a variety of enzymes is used to cleave the target-dependent cleavage structure, thereby indicating the presence of specific nucleic acid sequences or specific variations thereof.
Molecular Structure of Benzoic acid
NSDL National Science Digital Library
Benzoic acid is a medium-strong acid found in human foods such as berries, and is used as a plasticizer, insecticide, fungicide, an antifungal agent and in the manufacture of pharmaceuticals. It is more hydrophobic, water fearing, in comparison with other carboxylic acids and therefore can be extracted easily from all types of solvents. This acid is slightly soluble in water and has a melting point of 122 degrees Celsius. Benzoic acid is industrially manufactured from toluene, benzotrichloride and phthalic anhydride. It is purified by the process of sublimation, and the extremely pure form is used as a titrimetric and calorimetric standard in analytical chemistry.
Molecular Structure of Adipic acid
NSDL National Science Digital Library
Adipic acid is odorless and colorless white crystals or powder with a sour taste. Adipic acid is used primarily in the manufacture of nylon-6,6 polyamide and polyester polyols for polyurethane systems. It is also used for raw materials in pharmaceuticals, perfume fixatives, acidulants, leavening and buffering agents in non-alcoholic beverages, gelatins and puddings. In addition, adipic acid is used in manufacturing plasticizers and lubricants components. It is slightly soluble in water and soluble in alcohol and acetone. Adipic acid can be prepared from acetylene and acetic acid in the presence of tert-butyl peroxide. It has been manufactured from either cyclohexane or phenol.
Wilcher, M.E. (Pennsylvania State Univ., New Kensington, PA (US))
This work examines and compares the acid rain policies through the different political systems of Canada, Great Britain and the United States. Because the flow of acid rain can transcend national boundaries, acid rain has become a crucial international problem. According to the author, because of differences in governmental institutions and structure, the extent of governmental intervention in the industrial economy, the degree of reliance on coal for power generation, and the extent of acid rain damage, national responses to the acid rain problem have varied.
Acid Rain Experiments: Soil Buffering
NSDL National Science Digital Library
This experiment will help students understand that soil sometimes contains substances, like limestone, that buffer acids or bases, and that some salts in soil may also act as buffers. They will collect soil samples from their lawn, garden, or school and look for buffering effects by observing the pH change of an acid mixture poured through the samples. If the water collected from the sample is less acidic than the original mixture, then the soil is buffering some of the acid. If it does not change, then the soil may not be capable of buffering acids.
40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.
Code of Federal Regulations, 2012 CFR
...false Fatty acid polyamine condensate, phosphoric acid ester salts...6200 Fatty acid polyamine condensate, phosphoric acid ester salts...identified as fatty acid polyamine condensate, phosphate ester salts...uses are: (i) Release to water. Requirements as...
40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.
Code of Federal Regulations, 2011 CFR
...false Fatty acid polyamine condensate, phosphoric acid ester salts...6200 Fatty acid polyamine condensate, phosphoric acid ester salts...identified as fatty acid polyamine condensate, phosphate ester salts...uses are: (i) Release to water. Requirements as...
40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.
Code of Federal Regulations, 2013 CFR
...false Fatty acid polyamine condensate, phosphoric acid ester salts...6200 Fatty acid polyamine condensate, phosphoric acid ester salts...identified as fatty acid polyamine condensate, phosphate ester salts...uses are: (i) Release to water. Requirements as...
40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.
Code of Federal Regulations, 2014 CFR
...false Fatty acid polyamine condensate, phosphoric acid ester salts...6200 Fatty acid polyamine condensate, phosphoric acid ester salts...identified as fatty acid polyamine condensate, phosphate ester salts...uses are: (i) Release to water. Requirements as...
Effect of diets rich in oleic acid, stearic acid and linoleic acid on postprandial haemostatic factors in young healthy men
Kirsty A. Hunter; Lynn C. Crosbie; Graham W. Horgan; George J. Miller; Asim K. Dutta-Roy
The aim of the present study was to investigate the effects of stearic acid-, oleic acid- and linoleic acid-rich meals on postprandial haemostasis in young healthy volunteers whose background diets had been controlled for 14 d in a residential study. Six healthy male volunteers were assigned randomly to consume diets rich in stearic acid, oleic acid or linoleic acid for
Molecular Structure of Picric acid
NSDL National Science Digital Library
Picric Acid was first discovered in 1771 by a British Chemist named Peter Woulfe by treatment of indigo with nitric acid. It is most commonly seen in its yellow, water-soluble, crystalline form. For this reason, picric acid first saw use as a dyeing agent in textiles. However, around 1849 it was discovered (for obvious reasons) that picric acid is a shock, heat, and friction-sensitive explosive. Its first use as an explosive material came in military weaponry: torpedoes in particular due to its shock-sensitive nature not requiring a detonator to explode on contact with a target. However, picric acid was found to be highly corrosive to metals, making the weapons very difficult to handle and the acid itself difficult to store. Today, picric acid is used more widely as an ingredient in the manufacture of inert dyes and stable explosives such as dynamite.
Molecular Structure of Sorbic acid
NSDL National Science Digital Library
Sorbic acid is a colorless or white crystalline powder, with a weak characteristic odor and slightly acidic taste. It may be obtained from berries of the mountain ash or prepared synthetically by condensing crotonaldehyde and malonic acid in pyridine solution. Sorbic acid is a polyunsaturated fat used to inhibit molds and yeast, is a fungistatic agent for foods (especially cheeses, wine and baked goods). The main use of sorbic acid is as a preservative in foods, animal feeds, tobacco, cosmetics and pharmaceuticals, as well in packing materials for these substances and in other products that come in contact with human or animal skin in some way. Sorbic acid is also used as an intermediate for plasticizers and lubricants. Sorbic acid reacts with potassium to make potassium sorbate and with calcium to make calcium sorbate.
Esterification by the Plasma Acidic Water: Novel Application of Plasma Acid
NASA Astrophysics Data System (ADS)
Gu, Ling
This work explores the possibility of plasma acid as acid catalyst in organic reactions. Plasma acidic water was prepared by dielectric barrier discharge and used to catalyze esterification of n-heptanioc acid with ethanol. It is found that the plasma acidic water has a stable and better performance than sulfuric acid, meaning that it is an excellent acid catalyst. The plasma acidic water would be a promising alternative for classic mineral acid as a more environment friendly acid.
Lipid metabolism in the perfused chicken liver. The uptake and metabolism of oleic acid, elaidic acid, cis-vaccenic acid, trans-vaccenic acid and stearic acid
Bickerstaffe, R.; Annison, E. F.
Comparative studies were made of the uptake and metabolism of cis- and trans-octadecenoic acids by the perfused chicken liver. No differences were observed in the rates of uptake of the isomers. There was considerable incorporation of radioactivity into triglycerides and phospholipids, and some release of labelled lipid into the perfusate was observed. The cis-fatty acids were more readily incorporated into triglycerides than phospholipids, the reverse being true of the trans-fatty acids. Examination of the intramolecular distribution of fatty acids in triglycerides showed that the trans-fatty acid and stearate mainly occupied the 1- and 3-positions, and cis-fatty acids the 2-position. In the phospholipids phosphatidylcholine and phosphatidylethanolamine the trans-fatty acids again behaved like stearic acid and favoured the 1-position. No evidence was obtained of atypical patterns of uptake or metabolism of the trans-fatty acids. PMID:5472169
Vibrational structure of the polyunsaturated fatty acids eicosapentaenoic acid and arachidonic acid studied by infrared spectroscopy
NASA Astrophysics Data System (ADS)
Kiefer, Johannes; Noack, Kristina; Bartelmess, Juergen; Walter, Christian; Dörnenburg, Heike; Leipertz, Alfred
The spectroscopic discrimination of the two structurally similar polyunsaturated C 20 fatty acids (PUFAs) 5,8,11,14,17-eicosapentaenoic acid and 5,8,11,14-eicosatetraenoic acid (arachidonic acid) is shown. For this purpose their vibrational structures are studied by means of attenuated total reflection (ATR) Fourier-transform infrared (FT-IR) spectroscopy. The fingerprint regions of the recorded spectra are found to be almost identical, while the C-H stretching mode regions around 3000 cm -1 show such significant differences as results of electronic and molecular structure alterations based on the different degree of saturation that both fatty acids can be clearly distinguished from each other.
Metabolism of 14 C-labelled oleic acid, erucic acid and nervonic acid in rats
K. K. Carroll
1-14C-Oleic acid, 2-14C-erucic acid and 2-14C-nervonic acid were administered to rats by tail-vein and the distribution of radioactivity in liver lipids was determined\\u000a at intervals from 15 min to 6 hr after injection. High levels of activity were found after short time intervals which were\\u000a mainly associated with triglycerides in the case of oleic acid and with free fatty acids
Growth of nitric acid hydrates on thin sulfuric acid films
NASA Technical Reports Server (NTRS)
Iraci, Laura T.; Middlebrook, Ann M.; Wilson, Margaret A.; Tolbert, Margaret A.
Type I polar stratospheric clouds (PSCs) are thought to nucleate and grow on stratospheric sulfate aerosols (SSAs). To model this system, thin sulfuric acid films were exposed to water and nitric acid vapors (1-3 x 10(exp -4) Torr H2O and 1-2.5 x 10(exp -6) Torr HNO3) and subjected to cooling and heating cycles. Fourier Transform Infrared (FTIR) spectroscopy was used to probe the phase of the sulfuric acid and to identify the HNO3/H2O films that condensed. Nitric acid trihydrate (NAT) was observed to grow on crystalline sulfuric acid tetrahydrate (SAT) films. NAT also condensed in/on supercooled H2SO4 films without causing crystallization of the sulfuric acid. This growth is consistent with NAT nucleation from ternary solutions as the first step in PSC formation.
Bile Acid Metabolism and Signaling
Chiang, John Y. L.
Bile acids are important physiological agents for intestinal nutrient absorption and biliary secretion of lipids, toxic metabolites, and xenobiotics. Bile acids also are signaling molecules and metabolic regulators that activate nuclear receptors and G protein-coupled receptor (GPCR) signaling to regulate hepatic lipid, glucose, and energy homeostasis and maintain metabolic homeostasis. Conversion of cholesterol to bile acids is critical for maintaining cholesterol homeostasis and preventing accumulation of cholesterol, triglycerides, and toxic metabolites, and injury in the liver and other organs. Enterohepatic circulation of bile acids from the liver to intestine and back to the liver plays a central role in nutrient absorption and distribution, and metabolic regulation and homeostasis. This physiological process is regulated by a complex membrane transport system in the liver and intestine regulated by nuclear receptors. Toxic bile acids may cause inflammation, apoptosis, and cell death. On the other hand, bile acid-activated nuclear and GPCR signaling protects against inflammation in liver, intestine, and macrophages. Disorders in bile acid metabolism cause cholestatic liver diseases, dyslipidemia, fatty liver diseases, cardiovascular diseases, and diabetes. Bile acids, bile acid derivatives, and bile acid sequestrants are therapeutic agents for treating chronic liver diseases, obesity, and diabetes in humans. PMID:23897684
Biophysical Properties of Phenyl Succinic Acid Derivatised Hyaluronic Acid
Maria Teresa Neves-Petersen; Sřren Klitgaard; Esben Skovsen; Steffen B. Petersen; Kristoffer Třmmeraas; Khadija Schwach-Abdellaoui
Modification of hyaluronic acid (HA) with aryl succinic anhydrides results in new biomedical properties of HA as compared\\u000a to non-modified HA, such as more efficient skin penetration, stronger binding to the skin, and the ability to blend with hydrophobic\\u000a materials. In the present study, hyaluronic acid has been derivatised with the anhydride form of phenyl succinic acid (PheSA).\\u000a The fluorescence
Boswellic acid inhibits expression of acid sphingomyelinase in intestinal cells
Yao Zhang; Rui-Dong Duan
BACKGROUND: Boswellic acid is a type of triterpenoids with antiinflammatory and antiproliferative properties. Sphingomyelin metabolism generates multiple lipid signals affecting cell proliferation, inflammation, and apoptosis. Upregulation of acid sphingomyelinase (SMase) has been found in several inflammation-related diseases such as inflammatory bowel diseases, atherosclerosis, and diabetes. METHODS: The present study is to examine the effect of 3-acetyl-11-keto-?-boswellic acids (AKBA), a potent
Modification of hyaluronic acid with aromatic amino acids
I. Yu. Ponedel'kina; V. N. Odinokov; E. S. Vakhrusheva; M. T. Golikova; L. M. Khalilov; U. M. Dzhemilev
Hyaluronic acid was modified with aromatic amino acids (5-aminosalicylic, 4-aminosalicylic, anthranilic, and p-aminobenzoic) in the presence of 1-ethyl-3-[3-(dimethylamino)propyl]carbodiimide. The modified glycans contained 9–43% of arylamide groups and 10–33% of isoureidocarbonyl groups depending on the nature of the amino acid. Reduction with sodium borohydride allowed the conversion of isoureidocarbonyl groups into hydroxymethyl groups.
Molecular Structure of Phosphoric acid
NSDL National Science Digital Library
Phosphoric acid was first made in 1774 by K.W. Scheele and J.G. Gahn from bone ash. Phosphoric acid is made by treating calcium phosphate rock with sulfuric acid, followed by filtration. It is by this process that almost 10 tons of phosphoric acid are produced in the United States each year. The compound is primarily used to manufacture some pharmaceutical products, fertilizers and as a flavoring agent in coca-cola. The steel industry uses it to clean and rust-proof their steel. Phosphoric acid is also used in the process of soil stabilization, and as a catalyst in the production of propylene and butene polymers, ethylbenzene, and cumene. In recent years though the industry has moved away from using phosphoric acid as a ingredient in detergents because of the harmful effect that Phosphates have on lakes a process called lake eutrophication.
Molecular Structure of Butyric acid
NSDL National Science Digital Library
n-Butyric acid is a substance that was isolated from butter in 1869. Butyric acid means, in Latin, the acid of butter as it was first discovered in rancid butter. It is found most commonly in butter, but can also be present in some fruits. Butyric acid is also produced synthetically, through fermentation of various carbohydrates, to be used as a flavoring agent in various food products. Applications of butyric acid are as an additive to food, flavorings, varnishes, perfumes, pharmaceuticals and disinfectants. It is also used for the production of plastics, plasticizers, surfactants and textile auxiliaries. Butyric acid and its derivatives are also being seriously considered around the world as potential anticancer agents.
Butyric acid in functional constipation
Pituch, Aleksandra; Walkowiak, Jaros?aw
Butyric acid, a short-chain fatty acid, is a major energy source for colonocytes. It occurs in small quantities in some foods, and in the human body, it is produced in the large intestine by intestinalkacteria. This production can be reduced in some cases, for which butyric acid supplementation may be useful. So far, the use of butyric acid in the treatment of gastrointestinal disorders has been limited because of its specific characteristics such as its rancid smell and rapid absorption in the upper gastrointestinal tract. In the Polish market, sodium butyrate has been recently made available, produced by the modern technology of microencapsulation, which allows the active substance to reach the small and large intestines, where butyrate easily dissociates into butyric acid. This article presents the potential beneficial mechanisms of action of butyric acid in defecation disorders, which are primarily associated with reductions in pain during defecation and inflammation in the gut, among others. PMID:24868272
Aqueous solubility and acidity constants of cholic, deoxycholic, chenodeoxycholic, and u rsodeoxyc ho I ic acids
Yoshikiyo Moroi; Hideaki Itoh
Cholic acid, deoxycholic acid, chenodeoxycholic acid, and ursodeoxycholic acid were purified by a foam frac- tionation method. Using thermogravimetric analysis, the at- tached water molecule was found to be completely removed from solids of the latter three at 100°C, while cholic acid still had one water molecule of crystallization per two cholic acid molecules at that temperature. The acidity constants
Zirconium in sulfuric acid applications
Webster, R.T.; Yau, T.L.
Zirconium is one of the few metals that resists attack by sulfuric acid at concentrations up to 75% and temperatures to boiling and above. This capability makes zirconium a good structural metal for use in 40 to 65% H/sub 2/SO/sub 4/ up to boiling temperatures and for weak acid concentrations at elevated temperatures. Zirconium's corrosion properties in sulfuric acid solutions are compared with nickel base alloys. Examples of applications and limitations in the use of zirconium are presented.
Intestinal metabolism of fatty acids
Enser, M.
1. The effect of concentration on the oxidation and incorporation into lipids of lauric acid and linoleic acid by rings of rat small intestine has been studied in vitro. 2. In the absence of glucose, the oxidation of lauric acid in the range 0·01–5·0mm showed a maximum at 0·1mm. In the presence of glucose the maximum was at 0·5mm. The oxidation of linoleic acid in the presence of glucose increased throughout the concentration range 0·01–5·0mm. 3. The incorporation of lauric acid into lipids was maximal at 0·5–0·6mm in the presence of glucose, but at 10mm in the absence of glucose. At 0·8mm-lauric acid, in the presence of glucose, over 75% of the incorporated lauric acid was in triglycerides, but at 10mm they only contained 30%. The incorporation of glucose carbon into glycerides paralleled the incorporation of lauric acid. 4. In the range 0·01–2·5mm-linoleic acid the quantity incorporated into lipids increased. In the range 0·01–0·4mm linoleic acid was incorporated predominantly into triglycerides, but between 0·4 and 1·0mm most was in diglycerides, and between 2·5 and 5·0mm most was in monoglycerides. 5. The relationship of fatty acid concentration to the mechanism of absorption is discussed, together with the correlation between the distribution of the absorbed fatty acids within the tissue lipids and the lipase activity of intestinal mucosa. PMID:5837779
Piezoelectricity in protein amino acids
NASA Astrophysics Data System (ADS)
Lemanov, V. V.; Popov, S. N.; Pankova, G. A.
The piezoelectric activity of protein amino acids and their compounds has been measured using the pulse method at a frequency of 10 MHz. It has been established that, at room temperature, the piezoelectric effect is not observed in ?-glycine (achiral amino acid) and protein amino acids of the L modification, namely, methionine, phenylalanine, and tryptophan. An assumption has been made that this phenomenon is associated with the enhanced damping of elastic vibrations excited in samples due to the piezoelectric effect.
New syntheses of aminoalkylphosphonic acids
DeBardeleben, John Frederick
to remove any remaining benzoic acid, The aqueous layer was evaporated on a steam bath in vacuum. To the residue 100 ml, of ethyl alcohol was added. The resulting mixture was filtered while hot to remove sodium chloride. The alcohol was removed by dis.... Only three ? valine (VIII a), leucine (VIII b), and isoleucine (VIII c) ? corresponded to naturally occurring amino carboxylic acids. Mono- and dialkylmalonamidic acids (IX) were caused to react with sodium hypobromite, yielding the desired amino...
Acid site promotion of mordenite
W. J. Kiovsky; J. R. Goyette; T. M. Notermann
Ammonia adsorption isotherms for H-mordenite (10:1 silica-alumina) and partially dealuminated H-mordenite (13:1 silica-alumina) showed that dealumination generated new strong acid sites, in contrast to dealumination of Y-zeolite, which decreases first the weak and then the stronger acid sites. An IR spectroscopic study of 13:1 and 16:1 silica-alumina mordenites showed that the number of both Lewis and Broensted strong acid sites
Alkali-isomerized linoleic acid
D. E. Terry; D. H. Wheeler
Summary Alkali-isomerized linoleic acid and its methyl ester have been found to have boiling points higher than the corresponding\\u000a normal C18 acids and esters.\\u000a \\u000a By careful fractional distillation of methyl esters of alkali-isomerized C18 cottonseed acids, methyl linoleate of 95% or more purity is obtained consisting of 75% conjugated methyl linoleate and some\\u000a 20% of methyl ester of an altered linoleic
Fumaric acid production by fermentation
Carol A. Roa Engel; Adrie J. J. Straathof; Tiemen W. Zijlmans; Walter M. van Gulik; Luuk A. M. van der Wielen
The potential of fumaric acid as a raw material in the polymer industry and the increment of cost of petroleum-based fumaric\\u000a acid raises interest in fermentation processes for production of this compound from renewable resources. Although the chemical\\u000a process yields 112% w\\/w fumaric acid from maleic anhydride and the fermentation process yields only 85% w\\/w from glucose, the latter raw
Molecular Structure of Propionic acid
NSDL National Science Digital Library
Propanoic acid was named after the Greek word "Pro" for first and "pion" for fat, because it is the first fatty acid. It is a liquid and has a slightly pungent odor that can be characterized as rancid. Sweat, milk, and fermentation products all contain small amounts of this chemical. It can be synthesized from ethanol or ethylene and carbon monoxide. The calcium salt of propanoic acid is used as an antimolding agent and is an additive in breads. Esters of this carboxylic acid have a pleasant smell and taste and are used in the manufacture of fruit flavors and perfume bases. This compound is also found in a herbicide, called Silverado.
Acid pulses from snowmelt at acidic cone pond, New Hampshire
S. Fay Baird; Donald C. Buso; James W. Hornbeck
A study was undertaken to examine whether 'acid pulses' from snowmelt created permanent changes in a pond's chemistry. Water samples were collected from clearwater acidic Cone Pond in the White Mountain National Forest, New Hampshire. The pond, inlet, and outlet were intensively sampled throughout winter and early spring 1983–84. Thaws brought more H+ into upper waters of the pond, but
Naphthenic acids and surrogate naphthenic acids in methanogenic microcosms
Fervone M Holowenko; Michael D MacKinnon; Phillip M Fedorak
Naphthenic acids (NAs) are a complex mixture of naturally occurring acyclic and cyclic aliphatic carboxylic acids in petroleum. In the Athabasca oil sands, NAs have been identified as the largest component of dissolved organic matter in the tailings waters from oils sands extraction processes. They are the major contributor to the acute toxicity of the fine tailings wastewaters at the
Acid zeta function and ajoint acid zeta function
Jining Gao
In this paper we set up the theory of acid zeta function and ajoint acid zeta function, based on the theory, we point out a reason to doubt the truth of the Riemann hypothesis and also as a consequence, we give out some new RH equivalences.
No Potassium, No Acid: K+ Channels and Gastric Acid Secretion
NSDL National Science Digital Library
The gastric H+-K+-ATPase pumps H+ into the lumen and takes up K+ in parallel. In the acid-producing parietal cells, luminal KCNE2/KCNQ1 K+ channels play a pivotal role in replenishing K+ in the luminal fluid. Inactivation of KCNE2/KCNQ1 channels abrogates gastric acid secretion and dramatically modifies the architecture of gastric mucosa.
Acid rain on acid soil: a new perspective
E. C. Krug; C. R. Frink
Acid rain is widely believed to be responsible for acidifying soil and water in areas of North America and northern Europe. However, factors commonly considered to make landscapes susceptible to acidification by acid rain are the same factors long known to strongly acidify soils through the natural processes of soil formation. Recovery from extreme and widespread careless land use has
40 CFR 721.10679 - Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra...
Code of Federal Regulations, 2014 CFR
... 2014-07-01 false Carboxylic acid, substituted alkylstannylene ester, reaction products with inorganic acid tetra alkyl ester (generic). 721...Substances § 721.10679 Carboxylic acid, substituted alkylstannylene...
NASA Technical Reports Server (NTRS)
Orgel, Leslie
It has been supposed that for a nucleic acid analog to pair with RNA it must, like RNA, have a backbone with at least a sixatom repeat; a shorter backbone presumably would not stretch far enough to bind RNA properly. The Eschenmoser group has shown, however, that this first impression is incorrect.As they report in their new paper, Eschenmoser and co-workers ( I ) have now synthesized a substantial number of these polymers, which are called (L)-a-threofuranosyl oligonucleotides or TNAs. They are composed of bases linked to a threose sugar-phosphate backbone, with phosphodiester bonds connecting the nucleotides. The investigators discovered that pairs of complementary TNAs do indeed form stable Watson-Crick double helices and, perhaps more importantly, that TNAs form stable double helices with complementary RNAs and DNAs.
Acid rain on acid soil: a new perspective
Krug, E.C.; Frink, C.R.
Acid rain is widely believed to be responsible for acidifying soil and water in areas of North America and Northern Europe. However, factors commonly considered to make landscapes susceptible to acidification by acid rain are the same factors long known to strongly acidify soils through the natural processes of soil formation. Recovery from extreme and widespread careless land use has also occurred in regions undergoing acidification. There is evidence that acidification by acid rain is superimposed on long-term acidification induced by changes in land use and consequent vegetative succession. Thus, the interactions of acid rain, acid soil, and vegetation need to be carefully examined on a watershed basis in assessing benefits expected from proposed reductions in emissions of oxides of sulfur and nitrogen.
Microbial desulfonation of substituted naphthalenesulfonic acids and benzenesulfonic acids.
Zürrer, D; Cook, A M; Leisinger, T
Sulfur-limited batch enrichment cultures containing one of nine multisubstituted naphthalenesulfonates and an inoculum from sewage yielded several taxa of bacteria which could quantitatively utilize 19 sulfonated aromatic compounds as the sole sulfur source for growth. Growth yields were about 4 kg of protein per mol of sulfur. Specific degradation rates were about 4 to 14 mu kat/kg of protein. A Pseudomonas sp., an Arthrobacter sp., and an unidentified bacterium were examined. Each desulfonated at least 16 aromatic compounds, none of which served as a carbon source. Pseudomonas sp. strain S-313 converted 1-naphthalenesulfonic acid, 2-naphthalenesulfonic acid, 5-amino-1-naphthalenesulfonic acid, benzenesulfonic acid, and 3-aminobenzenesulfonic acid to 1-naphthol, 2-naphthol, 5-amino-1-naphthol, phenol, and 3-aminophenol, respectively. Experiments with 18O2 showed that the hydroxyl group was derived from molecular oxygen. PMID:3662502
Octadecylsulfuric acid. Properties of the acid, amine salts, and salts of amino acids
E. W. Maurer; A. J. Stirton; J. K. Weil
Summary Octadecanol, hexadecanol, tetradecanol, and dodecanol were sulfated with chlorosulfonic acid, and the corresponding alkylsulfuric\\u000a acids were isolated in a pure state as white crystalline solids with definite melting points.\\u000a \\u000a Octadecylsulfuric acid resembles sodium octadecyl sulfate in detergent and surface-active properties and in stability to hydrolysis\\u000a at equal concentrations of hydrogen ion. It is more soluble in water than sodium octadecyl
Determination of relative acid strength and acid amount of solid acids by Ar adsorption
Hiromi Matsuhashi; Ayumi Futamura
Relative acid strength and acid amount of solid acids (alumina, silica-alumina, sulfated zirconia, mordenite, ZSM-5, beta, Y, and reduced MoO3) are determined by argon adsorption technique. To obtain the heat of Ar adsorption and saturated adsorption amount, the adsorption isotherm is analyzed using the theory reported by Cremer and Flügge. The obtained heats of Ar adsorption and saturated adsorption amounts
Carbonic Acid Pretreatment of Biomass
G. Peter van Walsum; Kemantha Jayawardhana; Damon Yourchisin; Robert McWilliams; Vanessa Castleberry
This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. 1) Solidify the theoretical understanding of the binary CO2/H2O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. 2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. 3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. 4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. 5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic acid compared to water alone. 6) Determine optimal conditions for carbonic acid pretreatment of aspen wood. Optimal severities appeared to be in the mid range tested. ASPEN-Plus modeling and economic analysis of the process indicate that the process could be cost competitive with sulfuric acid if the concentration of solids in the pretreatment is maintained very high (~50%). Lower solids concentrations result in larger reactors that become expensive to construct for high pressure applications.
Carbonic Acid Retreatment of Biomass
Baylor university
This project sought to address six objectives, outlined below. The objectives were met through the completion of ten tasks. (1) Solidify the theoretical understanding of the binary CO{sub 2}/H{sub 2}O system at reaction temperatures and pressures. The thermodynamics of pH prediction have been improved to include a more rigorous treatment of non-ideal gas phases. However it was found that experimental attempts to confirm theoretical pH predictions were still off by a factor of about 1.8 pH units. Arrhenius experiments were carried out and the activation energy for carbonic acid appears to be substantially similar to sulfuric acid. Titration experiments have not yet confirmed or quantified the buffering or acid suppression effects of carbonic acid on biomass. (2) Modify the carbonic acid pretreatment severity function to include the effect of endogenous acid formation and carbonate buffering, if necessary. It was found that the existing severity functions serve adequately to account for endogenous acid production and carbonate effects. (3) Quantify the production of soluble carbohydrates at different reaction conditions and severity. Results show that carbonic acid has little effect on increasing soluble carbohydrate concentrations for pretreated aspen wood, compared to pretreatment with water alone. This appears to be connected to the release of endogenous acids by the substrate. A less acidic substrate such as corn stover would derive benefit from the use of carbonic acid. (4) Quantify the production of microbial inhibitors at selected reaction conditions and severity. It was found that the release of inhibitors was correlated to reaction severity and that carbonic acid did not appear to increase or decrease inhibition compared to pretreatment with water alone. (5) Assess the reactivity to enzymatic hydrolysis of material pretreated at selected reaction conditions and severity. Enzymatic hydrolysis rates increased with severity, but no advantage was detected for the use of carbonic acid compared to water alone. (6) Determine optimal conditions for carbonic acid pretreatment of aspen wood. Optimal severities appeared to be in the mid range tested. ASPEN-Plus modeling and economic analysis of the process indicate that the process could be cost competitive with sulfuric acid if the concentration of solids in the pretreatment is maintained very high ({approx}50%). Lower solids concentrations result in larger reactors that become expensive to construct for high pressure applications.
Robert J. Feldmann; Howard I. Maibach
We studied the percutaneous penetration of 21 organic chemicals. The experimental method consisted of the application of the chemical to the human forearm and quantitating its penetration through the skin by its appearance in urine.There was a great diversity in the ability of the chemicals to penetrate human skin. Compounds such as hippuric acid, nicotinic acid, and nitrobenzene support the
Individual Particle Morphology and Acidity
Esther Coz; Begońa Artíńano; Allen L. Robinson; Gary S. Casuccio; Traci L. Lersch; Spyros N. Pandis
The morphological characterization of particles during the Pittsburgh Air Quality Study (PAQS) suggests that particle shape and physical state depends on their acidity. The aerosol shape parameters measured by Computer-Controlled Scanning Electron Microscopy (CCSEM) are statistically different in periods when atmospheric particles are neutral and when they are acidic. High concentrations of particles smaller than 500 nm with high sulfur
Molecular Structure of Formic acid
NSDL National Science Digital Library
Formic Acid, also known as methanoic acid and hydrogencarboxylic acid, is the simplest organic acid. It is a colorless, toxic, corrosive liquid with a pungent, penetrating odor. In nature, it is found in the stings and bites of many insects of the order hymenoptera, including bees and ants. The principal use of formic acid is as a preservative and antibacterial agent in livestock feed. The largest single use of formic acid is as a silage additive in Europe, but this market hardly exists in the United States. When sprayed on fresh hay or other silage, it arrests certain decay processes and causes the feed to retain its nutritive value longer. In the poultry industry, it is sometimes added to silage to kill salmonella bacteria. It is also used in textile dyeing, leather tanning, as a solvent, in electroplating processes, in the manufacturing of lacquers, glass, vinyl resin plasticizers, and formate esters (for flavor and fragrance) and in the manufacture of fumigants. Formic acid is a strong reducing agent, and may act both as an acid and as an aldehyde because the carboxyl is bound to a hydrogen rather than an alkyl group.
This chapter discusses the major chemical processes by which acidic deposition interacts with soils. he focus is on forest soils, as the effects of acidic deposition on soils used for production of food and fiber are generally small compared to effects of agricultural practices s...
Getting Back to Basics (& Acidics)
ERIC Educational Resources Information Center
Rhodes, Sam
This article describes a few novel acid-base experiments intended to introduce students to the basic concepts of acid-base chemistry and provide practical examples that apply directly to the study of biology and the human body. Important concepts such as the reaction between carbon dioxide and water, buffers and protein denaturation, are covered.…
The Acid Rain Differential Game
Karl-Göran Mäler; Aart De Zeeuw
This paper considers an acid rain differential game. Countries emit sulphur which is partly transferred to other countries. Depositions above critical loads ultimately destroy the soil. Countries face a trade-off between the costs of emission reductions and the damage to the soil due to the depletion of the acid buffers. Because of the transboundary externalities the outcome will depend on
Acid rain & electric utilities II
This document presents reports which were presented at the Acid Rain and Electric Utilities Conference. Topics include environmental issues and electric utilities; acid rain program overview; global climate change and carbon dioxide; emissions data management; compliance; emissions control; allowance and trading; nitrogen oxides; and assessment. Individual reports have been processed separately for the United States Department of Energy databases.
Acid Rain: The Scientific Challenge.
ERIC Educational Resources Information Center
Godfrey, Paul J.
Documents the workings and findings of the Massachusetts Acid Rain Monitoring Project, which has pooled the volunteer efforts of more than 1,000 amateur and professional scientists since 1983. Reports on the origins of air pollution, the prediction of acid rain, and its effects on both water life and land resources. (JJK)
Acid Precipitation: Causes and Consequences.
ERIC Educational Resources Information Center
Babich, Harvey; And Others
This article is the first of three articles in a series on the acid rain problem in recent years. Discussed are the causes of acid precipitation and its consequences for the abiotic and biotic components of the terrestrial and aquatic ecosystems, and for man-made materials. (Author/SA)
Acid Rain: What's the Forecast?
ERIC Educational Resources Information Center
Bybee, Rodger
Discusses various types of acid rain, considered to be a century-old problem. Topics include: wet and dry deposition, effects on a variety of environments, ecosystems subject to detrimental effects, and possible solutions to the problem. A list of recommended resources on acid rain is provided. (BC)
Acid Rain: An Educational Opportunity?
ERIC Educational Resources Information Center
Marion, James I.
Deals with how educators can handle the subject of acid rain; illustrates suggestions with experiences of grade nine students visiting Frost Valley Environmental Education Center (Oliverea, New York) to learn scientific concepts through observation of outdoor phenomena, including a stream; and discusses acid rain, pH levels, and pollution control…
In 1981, simulated H2SO4 acid rain was applied to alfalfa and tall fescue and a 2:1 ratio of H2SO4:HNO3 acid rain was applied to alfalfa, tall fescue, barley, wheat, potato, tomato, radish, and corn crops growing in the open field at Corvallis, Oregon. Careful attention was given...
Concise Synthesis of Ximenynic Acid
Lutai Wang; Jiabin Li; Xiaowen Xue
An improved synthesis of ximenynic acid (1) starting from castor oil has been developed with the direct chlorination of ricinstearolic acid as the key step. By this modification, the synthetic route was more concise and economic. The separation of geometric somers was achieved by repeated urea fractionation.Supplemental materials are available for this article. Go the publisher's online edition of Synthetic
Preparation of pure stearic acid
J. M. Philipson; M. J. Heldman; L. L. Lyon; R. D. Vold
N order to interpret data on commercial soaps it is frequently necessary to investigate the behavior of systems of single pure soaps. For significant results, this often necessitates the preparation of purer fatty acids than any which can be purchased. Although there are numerous (1, 2) descriptions in the literature of methods for the preparation of pure stearic acid these
Functional nucleic acid probes and uses thereof
Nilsen-Hamilton, Marit
The present invention provides functional nucleic acid probes, and methods of using functional nucleic acid probes, for binding a target to carry out a desired function. The probes have at least one functional nucleic acid, at least one regulating nucleic acid, and at least one attenuator. The functional nucleic acid is maintained in an inactive state by the attenuator and activated by the regulating nucleic acid only in the presence of a regulating nucleic acid target. In its activated state the functional nucleic acid can bind to its target to carry out a desired function, such as generating a signal, cleaving a nucleic acid, or catalyzing a reaction.
Combined Acid Catalysis for Asymmetric Synthesis
Johnson, Jeff S.
Combined Acid Catalysis for Asymmetric Synthesis Michael T. Corbett University of North Carolina, 44, 19241942. Limitations of classical Brřnsted/Lewis Acid catalysis: · Poor reactivity (low acidity) · Low selectivity · High catalyst loading R X R X HMLn X Lewis Acid Catalysis Brřnsted Acid Catalysis X
Dana Moja; I. Badea
Cerium (IV) sulfate solution in sulfuric acid was used for the determination of o-aminobenzoic acid in sulfuric acid solution by potentiometric titration. The optima working conditions were set up for the quantitative determination of o-aminobenzoic acid. The method is simple, rapid and reliable. The effects of the acidity of the reaction medium and of the titrant concentration have been investigated.
Leveille-Webster, C
Increases in serum and tissue bile acid concentrations occur in hepatobiliary disease. In feline patients, the determination of serum bile acid concentrations is a sensitive and specific test for the diagnosis of acquired hepatobiliary disease and congenital portosystemic shunts. Because it is known that high concentrations of bile acids are cytotoxic, it has been speculated that they contribute to the pathological progression of hepatobiliary disorders. Recent evidence suggests the oral administration of the relatively nontoxic bile acid, ursodeoxycholate, can replace more hydrophobic hepatotoxic bile acids in the circulating pool and by doing so ameliorate the harmful effects of the latter. In addition, ursodeoxycholate has choleretic and immunomodulatory actions which may be of benefit in hepatobiliary disorder. PMID:9057484
Thermolysis of carboxylic acid salts
Khlestkin, R.N.; Khlestkina, V.L.; Usanov, N.G.; Gareev, V.M.
The dependence of the thermal stability of carboxylic acid salts on the nature of the anion and cation of the salt was studied. It was found that the capacity for thermal decomposition by salts of aliphatic, naphthenic, aromatic and heterocyclic carboxylic acids (with the exception of alkali salts) varies in inverse proportion to the values of the pK/sub a/ of the acids and to the values of the standard heats of formation of oxides (of the metal which forms the salt) relative to a monovalent bond with oxygen. An empirical equation which permits the thermal stability of many carboxylic acid salts to be predicted is given. Recommendations are developed for evaluating the relative activity of oxide and carbonate catalysts in reactions of vapor-phase conversion of aliphatic carboxylic acids to ketones and their operating temperatures.
NASA Astrophysics Data System (ADS)
Rice, C.; Ha, S.; Masel, R. I.; Waszczuk, P.; Wieckowski, A.; Barnard, Tom
The performance of formic acid fuel oxidation on a solid PEM fuel cell at 60 °C is reported. We find that formic acid is an excellent fuel for a fuel cell. A model cell, using a proprietary anode catalyst produced currents up to 134 mA/cm 2 and power outputs up to 48.8 mW/cm 2. Open circuit potentials (OCPs) are about 0.72 V. The fuel cell runs successfully over formic acid concentrations between 5 and 20 M with little crossover or degradation in performance. The anodic polarization potential of formic acid is approximately 0.1 V lower than that for methanol on a standard Pt/Ru catalyst. These results show that formic acid fuel cells are attractive alternatives for small portable fuel cell applications.
Molecular Structure of Galacturonic acid
NSDL National Science Digital Library
Galacturonic acid is the monobasic acid resulting from oxidation of the primary alcohol group of D-galactose to carboxyl. It is widely distributed as a constituent of pectins (compounds with heterogeneous grouping of acidic structural polysaccharides, found in fruit and vegetables), many plant gums, and mucilages (gummy substances obtained from certain plants, which are used as food stabilizers). Gums tend to be used as thickening and bulking agents in pharmaceutics, and they play a less obvious part in most plants. Once swallowed, their actions are no different from those of the mucilages. D-Galacturonic acid prepared from pectin can be used to synthesize vitamin C. Native pectin is a mixture of polysaccharides, with the major component a polymer of -D-galacturonic acid. Pectin has numerous other medical and pharmaceutical uses, for example in combination with plant hemicelluloses and lignin, may be useful dietary constituents in preventing coronary heart disease, diverticular disease, ulcerative colitis, and a variety of other Western diseases.
Molecular Structure of Linoleic acid
NSDL National Science Digital Library
Linoleic acid is a polyunsaturated fatty acid occurring widely in plant glycerides or fats. Common sources include many vegetable oils such as flax seed, safflower, soybean, peanut, and corn; some margarines; and dairy fats. It is a colorless to straw-colored liquid, insoluble in water, but soluble in alcohol and ether. Linoleic acid is easily oxidized by air and is combustible. It also appears as an aluminum salt, in the form of yellow lumps or powder, that is practically insoluble in water but soluble in oils and fixed alkalai hydroxides. Linoleic acid is essential in human nutrition and is used also for soaps, animal feeds, paints, drying protective coatings, emulsifying or smoothing and wetting agents, and in biochemical research. The conjugated form of linoleic acid or CLA has been associated with health benefits such as lowered risk of cancer and atherosclerosis. Prepared CLA is available as a supplement. However, foods high in CLA content could be used.
Atmospheric dust and acid rain
Hedin, L.O.; Likens, G.E.
Why is acid rain still an environmental problem in Europe and North America despite antipollution reforms? The answer really is blowing in the wind: atmospheric dust. These airborne particles can help neutralize the acids falling on forests, but dust levels are unusually low these days. In the air dust particles can neutralize acid rain. What can we do about acid rain and atmospheric dust? Suggestions range from the improbable to the feasible. One reasonable suggestion is to reduce emissions of acidic pollutants to levels that can be buffered by natural quantities of basic compounds in the atmosphere; such a goal would mean continued reductions in sulfur dioxide and nitrogen oxides, perhaps even greater than those prescribed in the 1990 Amendments to the Clean Air Act in the U.S. 5 figs.
Synthesis of higher monocarboxylic acids
Taikov, B.F.; Novakovskii, E.M.; Zhelkovskaya, V.P.; Shadrova, V.N.; Shcherbik, P.K.
Brown-coal and peat waxes contain higher monocarboxylic acids, alcohols and esters of them as their main components. In view of this, considerable interest is presented by the preparation of individual compounds among those mentioned above, which is particularly important in the study of the composition and development of the optimum variants of the chemical processing of the waxes. In laboratory practice, to obtain higher monocarboxylic acids use is generally made of electrosynthesis according to Kolbe which permits unbranched higher aliphatic acids with given lengths of the hydrocarbon chain to be obtained. The aim of the present work was to synthesize higher monocarboxylic acids: arachidic, behenic, lignoceric, pentacosanoic, erotic, heptacosanoic, montanic, nonacosanoic, melissic, dotriacontanoic and tetratriacontanoic, which are present in waxes. Characteristics of synthesized acids are tabulated. 20 refs.
40 CFR 721.10512 - Fatty acid maleic acid amides (generic).
Code of Federal Regulations, 2014 CFR
... 31 2014-07-01 2014-07-01 false Fatty acid maleic acid amides (generic). 721.10512 Section 721.10512...for Specific Chemical Substances § 721.10512 Fatty acid maleic acid amides (generic). (a) Chemical...
40 CFR 180.550 - Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues.
Code of Federal Regulations, 2012 CFR
...2012-07-01 2012-07-01 false Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues. 180.550 Section... Specific Tolerances § 180.550 Arsanilic acid [(4-aminophenyl) arsonic acid];...
40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.
Code of Federal Regulations, 2012 CFR
...2012-07-01 2012-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection...Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid...
40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.
Code of Federal Regulations, 2014 CFR
...2014-07-01 2014-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection...Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid...
40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.
Code of Federal Regulations, 2014 CFR
...2014-07-01 2014-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection...Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid...
40 CFR 721.10512 - Fatty acid maleic acid amides (generic).
Code of Federal Regulations, 2013 CFR
... 32 2013-07-01 2013-07-01 false Fatty acid maleic acid amides (generic). 721.10512 Section 721.10512...for Specific Chemical Substances § 721.10512 Fatty acid maleic acid amides (generic). (a) Chemical...
40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.
Code of Federal Regulations, 2013 CFR
...2013-07-01 2013-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection...Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid...
40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.
Code of Federal Regulations, 2013 CFR
...2013-07-01 2013-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection...Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid...
78 FR 55644 - Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption
Federal Register 2010, 2011, 2012, 2013, 2014
...FRL-9396-9] Styrene, Copolymers with Acrylic Acid and/or Methacrylic Acid; Tolerance Exemption AGENCY: Environmental Protection...for residues of styrene, copolymers with acrylic acid and/or methacrylic acid, with none and/or...
40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.
Code of Federal Regulations, 2010 CFR
...2010-07-01 2010-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection...Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid...
40 CFR 721.2086 - Coco acid triamine condensate, polycarboxylic acid salts.
Code of Federal Regulations, 2011 CFR
...2011-07-01 2011-07-01 false Coco acid triamine condensate, polycarboxylic acid salts. 721.2086 Section 721.2086 Protection...Specific Chemical Substances § 721.2086 Coco acid triamine condensate, polycarboxylic acid...
40 CFR 180.550 - Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues.
Code of Federal Regulations, 2011 CFR
...2011-07-01 2011-07-01 false Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues. 180.550 Section... Specific Tolerances § 180.550 Arsanilic acid [(4-aminophenyl) arsonic acid];...
40 CFR 180.550 - Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues.
Code of Federal Regulations, 2010 CFR
...2010-07-01 2010-07-01 false Arsanilic acid [(4-aminophenyl) arsonic acid]; tolerances for residues. 180.550 Section... Specific Tolerances § 180.550 Arsanilic acid [(4-aminophenyl) arsonic acid];...
40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.
Code of Federal Regulations, 2010 CFR
...2010-07-01 2010-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection...Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid...
40 CFR 721.3620 - Fatty acid amine condensate, polycarboxylic acid salts.
Code of Federal Regulations, 2011 CFR
...2011-07-01 2011-07-01 false Fatty acid amine condensate, polycarboxylic acid salts. 721.3620 Section 721.3620 Protection...Specific Chemical Substances § 721.3620 Fatty acid amine condensate, polycarboxylic acid...
Nonprotein Amino Acids from Spark Discharges and Their Comparison with the Murchison Meteorite Amino Acids
Wolman, Yecheskel; Haverland, William J.; Miller, Stanley L.
All the nonprotein amino acids found in the Murchison meteorite are products of the action of electric discharge on a mixture of methane, nitrogen, and water with traces of ammonia. These amino acids include ?-amino-n-butyric acid, ?-aminoisobutyric acid, norvaline, isovaline, pipecolic acid, ?-alanine, ?-amino-n-butyric acid, ?-aminoisobutyric acid, ?-aminobutyric acid, sarcosine, N-ethylglycine, and N-methylalanine. In addition, norleucine, alloisoleucine, N-propylglycine, N-isopropylglycine, N-methyl-?-alanine, N-ethyl-?-alanine ?,?-diaminopropionic acid, isoserine, ?,?-diaminobutyric acid, and ?-hydroxy-?-aminobutyric acid are produced by the electric discharge, but have not been found in the meteorite. PMID:16591973
Caldensinic acid, a prenylated benzoic acid from Piper caldense
Giovana C. Freitas; Rodrigo O. Saga Kitamura; Joăo Henrique G. Lago; Maria Claudia M. Young; Elsie F. Guimarăes; Massuo J. Kato
The CH2Cl2 and MeOH extracts from leaves of Piper caldense were subjected to chromatographic separation procedures to afford the new prenylated benzoic acid, caldensinic acid (3-[(2?E,6?E,10?E)-11?-carboxy-3?,7?,15?-trimethylhexadeca-2?,6?,10?,14?-tetraenyl]-4,5-dihydroxybenzoic acid) whose structure was determined by spectral analysis, mainly NMR (1H, 13C, HSQC, HMBC) and ESI-MS. The natural compound and derivatives displayed antifungal activity against the phytopathogenic fungi Cladosporium cladosporioides and C. sphaerospermum by
Alkaline cleavage of hydroxy unsaturated fatty acids. I. Ricinoleic acid and lesquerolic acid
M. J. Diamond; R. G. Binder; T. H. Applewhite
The effects of temperature and media on the fusion of ricinoleic and lesquerolic acid derivatives with concentrated aqueous\\u000a alkali were examined. Improved yields of?-hydroxy acids were obtained by use of excess 2-octanol. The effect of excess 2-octanol is discussed in relation to a recently\\u000a proposed reaction mechanism.
Determination of polyfluoroalkyl phosphoric acid diesters, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, perfluoroalkyl carboxylic acids, and perfluoroalkane sulfonic acids in lake trout from the Great Lakes region.
Guo, Rui; Reiner, Eric J; Bhavsar, Satyendra P; Helm, Paul A; Mabury, Scott A; Braekevelt, Eric; Tittlemier, Sheryl A
A comprehensive method to extract perfluoroalkyl carboxylic acids, perfluoroalkane sulfonic acids, perfluoroalkyl phosphonic acids, perfluoroalkyl phosphinic acids, and polyfluoroalkyl phosphoric acid diesters simultaneously from fish samples has been developed. The recoveries of target compounds ranged from 78 % to 121 %. The new method was used to analyze lake trout (Salvelinus namaycush) from the Great Lakes region. The results showed that the total perfluoroalkane sulfonate concentrations ranged from 0.1 to 145 ng/g (wet weight) with perfluorooctane sulfonate (PFOS) as the dominant contaminant. Concentrations in fish between lakes were in the order of Lakes Ontario ? Erie > Huron > Superior ? Nipigon. The total perfluoroalkyl carboxylic acid concentrations ranged from 0.2 to 18.2 ng/g wet weight. The aggregate mean perfluorooctanoic acid (PFOA) concentration in fish across all lakes was 0.045 ± 0.023 ng/g. Mean concentrations of PFOA were not significantly different (p > 0.1) among the five lakes. Perfluoroalkyl phosphinic acids were detected in lake trout from Lake Ontario, Lake Erie, and Lake Huron with concentration ranging from non-detect (ND) to 0.032 ng/g. Polyfluoroalkyl phosphoric acid diesters were detected only in lake trout from Lake Huron, at levels similar to perfluorooctanoic acid. PMID:22722738
Nucleic Acid Chaperone Activity of HIV1
Levin, Judith G.
Nucleic Acid Chaperone Activity of HIV1 Nucleocapsid Protein: Critical Role in Reverse ............................................................................ 218 II. Structure and Nucleic Acid Binding Properties of HIV1 NC ........................................................................... 219 A. Specific and Nonspecific Nucleic Acid Binding .............................. 220 B. Structural
Macromolecular Organic Acids in the Murchison Meteorite
NASA Astrophysics Data System (ADS)
Watson, J. S.; Sephton, M. A.; Gilmour, I.
This study has detected bound organic acids within the Murchison meteorite organic macromolecule. Benzoic acid was the most abundant compound; other abundant compounds include C1 and C2 benzoic acids. Their origin and significance will be discussed.
Acid preservation systems for food products
Tiberio, J. E.; Cirigiano, M. C.
Fumaric acid is used in combination with critical amounts of acetic acid to preserve acid containing food products from microbiological spoilage in the absence of or at reduced levels of chemical preservative.
Cholesterolaemic effect of palmitic acid in relation to other dietary fatty acids
Margaret A French; Kalyana Sundram; M Thomas Clandinin
The effect of dietary intake of high palmitic acid levels in combination with other fatty acids in normal subjects was assessed. Palmitic acid (10% of energy) was fed in conjunction with decreasing levels of linoleic acid to determine if a threshold level of linoleic acid prevented palmitic acid from being hypercholesterolaemic. Healthy subjects received each of the diet treatments for
Growth temperature affects accumulation of exogenous fatty acids and fatty acid composition in Schizosaccharomyces pombe
Virginia M. McDonough; Therese M. Roth
The incorporation of exogenously supplied fatty acids, palmitic acid, palmitoleic acid, oleic acid and linoleic acid, was examined in the yeast Schizosaccharomyces pombe at two growth temperatures, 20 °C and 30 °C. Fatty acids supplied to S. pombe in the growth medium were found to be preferentially incorporated into the cells, becoming a dominant species. The relative increase in exogenous
Hadi Alkarawi, H; Zotz, G
Phytic acid or phytate, the free-acid form of myo-inositolhexakiphosphate, is abundant in many seeds and fruits, where it represents the major storage form of phosphorus. Although also known from other plant tissues, available reports on the occurrence of phytic acid, e.g. in leaves, have never been compiled, nor have they been critically reviewed. We found 45 published studies with information on phytic acid content in leaves. Phytic acid was almost always detected when studies specifically tried to detect it, and accounted for up to 98% of total P. However, we argue that such extreme values, which rival findings from storage organs, are dubious and probably result from measurement errors. Excluding these high values from further quantitative analysis, foliar phytic acid-P averaged 2.3 mg·g(-1) , and represented, on average, 7.6% of total P. Remarkably, the ratio of phytic acid-P to total P did not increase with total P, we even detected a negative correlation of the two variables within one species, Manihot esculenta. This enigmatic finding warrants further attention. PMID:24341824
Terahertz spectrum of gallic acid
NASA Astrophysics Data System (ADS)
Wu, Meng; Zhao, Guozhong; Wang, Haiyan; Liang, Chengshen
Gallic acid is natural polyphenol compound found in many green plants. More and more experiments have demonstrated that the gallic acid has comprehensive applications. In the field of medicine, the gallic acid plays an important role in antianaphylaxis, antineoplastic, antimycotic, anti-inflammatory, antivirotic, antiasthmatic and inhibiting the degradation of insulin. It also has a lot of applications in chemical industry, food industry and light industry. So it is important to study the terahertz time-domain spectroscopy of gallic acid. Terahertz time-domain spectroscopy (THz-TDS) is a new coherent spectral technology based on the femtosecond laser. In this work, the spectral characteristics of gallic acid in the range of 0.4 THz to 2.6 THz have been measured by THz-TDS. We obtained its absorption and refraction spectra at room temperature. The vibration absorption spectrum of the single molecule between 0.4 THz and 2.6 THz is simulated based on the Density Functional Theory (DFT). It is found that the gallic acid has the spectral response to THz wave in this frequency range. The results show the abnormal dispersion at 1.51 THz and 2.05 THz. These results can be used in the qualitative analysis of gallic acid and the medicine and food inspection.
Ion chromatographic determination of acidity.
De Borba, B M; Kinchin, C M; Sherman, D; Cook, T K; Dasgupta, P K; Srinivasan, K; Pohl, C A
The practice of determining acid concentrations by titrations has remained unchanged for more than a century. We introduce a new approach to the determination of acid concentrations based on cation exchange chromatography. We demonstrate the ability of sulfonated styrene-divinylbenzene based stationary phases to separate the hydrogen ion from other monovalent cations. The eluent is a dilute solution of a neutral salt, sometimes containing a small concentration of the corresponding acid, e.g., sodium ethanesulfonate, pH adjusted with ethanesulfonic acid. The high equivalent conductance (approximately 350 S.cm2/equiv) of H+ and relatively low eluent concentration allows sensitive conductometric detection of H+, down to the 50 microM level under favorable conditions. The conductometric response to H+ can be linear over a wide range of H+ concentrations, from sub-millimolar to several molar concentrations. The system allows the rapid quantitation of strong acids; weak acids can also be determined depending on pKa and injected concentration. The determinations of several strong and weak acids are presented along with factors that govern their chromatographic analysis. PMID:10655640
Anticonvulsant activity of cyclopentano amino acids
Robert Zand; Ivan Izquierdo
The hypothesis that certain amino acid analogues possessing a five-membered ring structure or amino acid analogues that can be viewed as fragments derived from such a ring would have anticonvulsant activity was proposed and tested. The compounds 1-aminocyclopentane carboxylic acid, 1-amino-3-methylcyclopentane carboxylic acid, 3-aminotetrahydrothiophene carboxylic acid, and a-aminoisobutyric acid were found to protect rats against seizures in the maximal electroshock
Nucleic acid arrays and methods of synthesis
Sabanayagam, Chandran R. (Allston, MA); Sano, Takeshi (Needham, MA); Misasi, John (Syracuse, NY); Hatch, Anson (Seattle, WA); Cantor, Charles (Del Mar, CA)
The present invention generally relates to high density nucleic acid arrays and methods of synthesizing nucleic acid sequences on a solid surface. Specifically, the present invention contemplates the use of stabilized nucleic acid primer sequences immobilized on solid surfaces, and circular nucleic acid sequence templates combined with the use of isothermal rolling circle amplification to thereby increase nucleic acid sequence concentrations in a sample or on an array of nucleic acid sequences.
Extraction of uranium values from phosphoric acid
T. Largman; S. Sifniades; A. A. Tunick
Aqueous phosphoric acid solutions containing uranium values are contacted with an organic solution of a mixture of organophosphorus compounds produced from a carboxylic acid and pcl3 in the presence of water or from corresponding acid halides or anhydrides and phosphorous acid to extract the uranium values. The organophorus compounds generally include an alkane-1,1,2triphosphonic acid or a 1-hydroxy-1,1-alkanediphosphonic acid or both,
Oxidation of Benzaldehyde to Benzoic Acid
Hongyan Yan; Chunsheng Liu; Genxiang Luo
Benzaldehyde was oxidized to benzoic acid using Na2WO4·2H2O as a catalyst. Different factors, such as different acidic additives, the reaction time, the amount of catalyst, and hydrogen peroxide dosage, on the isolated yield of benzoic acid were investigated. The effects of surfactants on yield of benzoic acid were also discussed in the acid-free system. The results indicated that both acidic
Oligomer distribution in concentrated lactic acid solutions
Dung T. Vu; Aspi K. Kolah; Navinchandra S. Asthana; Lars Peereboom; Carl T. Lira; Dennis J. Miller
Lactic acid (2-hydroxypropanoic acid) is a significant platform chemical for the biorenewable economy. Concentrated aqueous solutions of lactic acid (>30wt.%) contain a distribution of oligomers that arise via intermolecular esterification. As a result, the titratable acidity changes non-linearly with acid concentration. In this work, the oligomer distribution of lactic acid is characterized using GC, GC\\/MS, and HPLC to extend existing
Naphthenic acid corrosion literature survey
Babaian-Kibala, E. [Nalco/Exxon Energy Chemicals, Sugar Land, TX (United States); Nugent, M.J. [Tosco Refining Co., Linden, NJ (United States)
Naphthenic acid corrosion is a growing concern for refineries processing crudes containing high levels of naphthenic acid. Due to this concern initiatives in place to better understand the mechanism of corrosion for mitigating the corrosion. During the 1996 Fall Corrosion Group, organized existing literature relevant to the literature search. Committee Week, NACE International many refineries have and evaluate methods T-8 Refining Industry a task group, T-8-22, to perform a review and compilation of naphthenic acid corrosion. This paper provides a summary of the literature research.
Atwill, L.
Acid rain is discussed in a question and answer format. The article is aimed at educating sport fishermen on the subject, and also to encourage them to write their congressmen, senators, and the President about the acid rain problem. The article also announces the availability of an acid rain test kit available through the magazine, ''Sports Afield.'' The kit consists of pH-test paper that turns different shades of pink and blue according to the pH of the water tested. The color of the test paper is then compared to a color chart furnished in the kit and an approximate pH can be determined.
Drilling fluids containing amps, acrylic acid, itaconic acid polymer
Bardoliwalla, D.F.
This patent describes an aqueous drilling fluid having present in an amount sufficient to reduce fluid loss of the drilling fluid, at least one polymer of (1) from about 5% to about 50% by weight of 2-acrylamido-2-methylpropane sulfonic acid and (2) from about 95% to about 50% by weight of a second component, there being from 100% to about 80% by weight of acrylic acid and from 0% by weight to about 20% by weight of itaconic acid in the second component. The polymer has a weight average molecular weight of between about 50,000 to about 1,000,000 being in its free acid or partially or completely neutralized form and being at least water dispersible. A method is described of drilling a well into a subterranean formation in which an aqueous drilling fluid is circulated into the well. The step of circulating the drilling fluid contains in an amount sufficient to reduce fluid loss of the drilling fluid, at least one polymer of (1) from about 5% to about 50% by weight of 2-acrylamido-2-methylpropane sulfonic acid and (2) from about 95% to about 50% by weight of a second component. There is from 100% to about 80% by weight of acrylic acid and from 0% by weight to about 20% by weight of itaconic acid in the second component. The polymer has weight average molecular weight of between about 50,000 to about 1,000,000 in its free acid or partially or completely neutralized form and is at least water dispersible.
Gallic Acid, Ellagic Acid and Pyrogallol Reaction with Metallic Iron
J. A. Jaén; L. González; A. Vargas; G. Olave
The reaction between gallic acid, ellagic acid and pyrogallol with metallic iron was studied using infrared and Mössbauer\\u000a spectroscopy. Most hydrolysable tannins with interesting anticorrosive or inhibition properties are structurally related to\\u000a these compounds, thus they may be used as models for the study of hydrolysable tannins and related polyphenols. The interaction\\u000a was followed up to 3 months. Results indicated
Docosahexaenoic acid affects arachidonic acid uptake in megakaryocytes
Schick, P.K.; Webster, P.
Dietary omega 3 fatty acids are thought to prevent atherosclerosis, possibly by modifying platelet (PT) function and arachidonic acid (20:4) metabolism. The study was designed to determine whether omega 3 fatty acids primarily affect 20:4 metabolism in megakaryocytes (MK), bone marrow precursors of PT, rather than in circulating PT. MK and PT were isolated from guinea pigs and incubated with (/sup 14/C)-20:4 (0.13uM). Docosahexaenoic acid (22:6) is a major omega 3 fatty acid in marine oils. The incubation of MK with 22:6 (0.1, 1.0 uM) resulted in the decrease of incorporation of (/sup 14/C)-20:4 into total MK phospholipids, 16% and 41% respectively. Alpha-linolenic acid (18:3), a major omega 3 fatty acid present in American diets, had no effect on 20:4 uptake in MK. 22:6 primarily affected the uptake of (/sup 14/C)-20:4 into phosphatidylethanolamine (PE) and phosphatidylserine (PS) in MK. In MK, 22:6 (0.1, 1.0 uM) caused a decrease of incorporation of (/sup 14/C)-20:4 into PE, 21% and 55% respectively; a decrease into PS, 16% and 48% respectively; but only a decrease of 4% and 18%, respectively, into phosphatidylcholine; and a decrease of 3% and 21% into phosphatidylinositol 22:6 (3.0 uM) had no effect on the uptake of AA into PT phospholipids. The study shows that 22:6 has a selective effect on AA uptake in MK and that the acylation or transacylation of PE and PS are primarily affected. 22:6 and other marine omega 3 fatty acids appear to primarily affect megakaryocytes which may result in the production of platelets with abnormal content and compartmentalization of AA.
Enhanced acid tolerance of Rhizopus oryzae during fumaric acid production.
Liu, Ying; Lv, Chunwei; Xu, Qing; Li, Shuang; Huang, He; Ouyang, Pingkai
Ensuring a suitable pH in the culture broth is a major problem in microorganism-assisted industrial fermentation of organic acids. To address this issue, we investigated the physiological changes in Rhizopus oryzae at different extracellular pH levels and attempted to solve the issue of cell shortage under low pH conditions. We compared various parameters, such as membrane fatty acids' composition, intracellular pH, and adenosine triphosphate (ATP) concentration. It was found that the shortage of intracellular ATP might be the main reason for the low rate of fumaric acid production by R. oryzae under low pH conditions. When 1 g/l citrate was added to the culture medium at pH 3.0, the intracellular ATP concentration increased from 0.4 to 0.7 µmol/mg, and the fumaric acid titer was enhanced by 63% compared with the control (pH 3.0 without citrate addition). The final fumaric acid concentration at pH 3.0 reached 21.9 g/l after 96 h of fermentation. This strategy is simple and feasible for industrial fumaric acid production under low pH conditions. PMID:25190324
GHB - Gamma-Hydroxybutyric Acid
... Ribbon Week DEA Red Ribbon Week Patch Program GHB - Gamma-Hydroxybutyric Acid Last Updated: Monday, August 4, ... in water, juice, or alcohol. In liquid form, GHB is clear and colorless and slightly salty in ...
The U.S. Environmental Protection Agency (EPA) is conducting an intensive characterization and human exposure monitoring program of acid species and related air pollutants in an urban environment. he EPA's Atmospheric Research and Exposure Assessment Laboratory (AREAL) in coopera...
Antibiofilm Properties of Acetic Acid
Bjarnsholt, Thomas; Alhede, Morten; Jensen, Peter Řstrup; Nielsen, Anne K.; Johansen, Helle Krogh; Homře, Preben; Hřiby, Niels; Givskov, Michael; Kirketerp-Mřller, Klaus
Bacterial biofilms are known to be extremely tolerant toward antibiotics and other antimicrobial agents. These biofilms cause the persistence of chronic infections. Since antibiotics rarely resolve these infections, the only effective treatment of chronic infections is surgical removal of the infected implant, tissue, or organ and thereby the biofilm. Acetic acid is known for its antimicrobial effect on bacteria in general, but has never been thoroughly tested for its efficacy against bacterial biofilms. In this article, we describe complete eradication of both Gram-positive and Gram-negative biofilms using acetic acid both as a liquid and as a dry salt. In addition, we present our clinical experience of acetic acid treatment of chronic wounds. In conclusion, we here present the first comprehensive in vitro and in vivo testing of acetic acid against bacterial biofilms. PMID:26155378
Ondrey, G.; Shanley, A.
Acid recovery may be expensive, but rising transportation and landfill costs may soon make it the only alternative. Traditionally, acids used in processes from titanium dioxide production to gasoline alkylation and metal pickling were neutralized and discharged into waterways or injected into deep wells. Today, however, discharge permits are being phased out in many countries, and deep well injection is coming under closer scrutiny. An even cheaper option was selling spent acid to fertilizer producers, who used it to dissolve phosphate ores. Health concerns, a depressed fertilizer market and tightening disposal regulations for gypsum byproduct have dried up this option. The paper discusses the processes and costs involved in spent acid regeneration, gypsum-free gas treatments, and problems with explosive contaminants.
Dried Acid Mine Drainage Residuals
Dried acid mine drainage residuals that are formed during treatment of the drainage. The USGS has pioneered a new use for these residuals that are currently a disposal challenge, using them to filter phosphorus from agricultural and municipal wastewaters....
Molecular Structure of Retinoic acid
NSDL National Science Digital Library
Retinoic acid is a yellow to light-orange crystalline powder, that is insoluble in water and slightly soluble in alcohol. Retinoic acid is a natural metabolite of vitamin A which participates in many of the known functions of vitamin A and may be the active agent in tetragenesis (still under investigation). Retinoic acid is used to improve the appearance and texture of the skin. It is also used in the treatment of certain skin diseases such as acne, psoriasis, diarier's disease and ichthyosis. Mild side-effects to the gel, primarily skin irritation, are common. Common side-effects associated with the oral formulation are: headache, dry skin, peeling skin, alopecia and high blood lipids. Retinoic acid is also very potent in promoting growth and controlling differentiation and maintenance of epithelial tissues in vitamin A deficient animals.
Molecular Structure of Abscisic acid
NSDL National Science Digital Library
Abscisic acid (ABA) was first identified and characterized by Frederick Addicott in 1963. ABA is a naturally occurring compound in plants synthesized partially in the chloroplasts. It is a phytohormone that plays an important role in regulating transpiration, stress responses, germination of seeds and embryogenesis in plants. Abscisic acid influences most aspects of plant growth and development to some level, in part due to interactions with other phytohormones. Abscisic acid also promotes abscission of leaves and fruits, and for this reason the name abscisic is given. This plant hormone is the key factor in the adaptation of the plant to environmental stresses such as salinity, drought or water loss, and freezing temperatures. Abscisic acid promotes dormancy and helps the plant tolerate stressful conditions by suspending primary and secondary growth.
Low acid producing solid propellants
NASA Technical Reports Server (NTRS)
Bennett, Robert R.
The potential environmental effects of the exhaust products of conventional rocket propellants have been assessed by various groups. Areas of concern have included stratospheric ozone, acid rain, toxicity, air quality and global warming. Some of the studies which have been performed on this subject have concluded that while the impacts of rocket use are extremely small, there are propellant development options which have the potential to reduce those impacts even further. This paper discusses the various solid propellant options which have been proposed as being more environmentally benign than current systems by reducing HCI emissions. These options include acid neutralized, acid scavenged, and nonchlorine propellants. An assessment of the acid reducing potential and the viability of each of these options is made, based on current information. Such an assessment is needed in order to judge whether the potential improvements justify the expenditures of developing the new propellant systems.
Controlling acid rain : policy issues
Fay, James A.
The policy and regulatory ramifications of U.S. acid rain control programs are examined; particularly, the alternative of a receptor-oriented strategy as constrasted to emission-oriented proposals (e.g., the Mitchell bill) ...
Nitrate and Prussic Acid Poisoning
Stichler, Charles; Reagor, John C.
Nitrate and prussic acid poisoning in cattle are noninfectious conditions that can kill livestock. This publication explains the causes and symptoms of these conditions as well as preventive measures and sampling and testing steps....
Abiotic synthesis of fatty acids
NASA Technical Reports Server (NTRS)
Leach, W. W.; Nooner, D. W.; Oro, J.
The formation of fatty acids by Fischer-Tropsch-type synthesis was investigated with ferric oxide, ammonium carbonate, potassium carbonate, powdered Pueblito de Allende carbonaceous chondrite, and filings from the Canyon Diablo meteorite used as catalysts. Products were separated and identified by gas chromatography and mass spectrometry. Iron oxide, Pueblito de Allende chondrite, and Canyon Diablo filings in an oxidized catalyst form yielded no fatty acids. Canyon Diablo filings heated overnight at 500 C while undergoing slow purging by deuterium produced fatty acids only when potassium carbonate was admixed; potassium carbonate alone also produced these compounds. The active catalytic combinations gave relatively high yields of aliphatic and aromatic hydrocarbons; substantial amounts of n-alkenes were almost invariably observed when fatty acids were produced; the latter were in the range C6 to C18, with maximum yield in C9 or 10.
Gamma Hydroxybutyric Acid (GHB) Intoxication
Phillip E. Mason; William P. Kerns II
Gamma-aminobutyric acid (GABA) was discovered as the predominant inhibitory central nervous sys- tem (CNS) neurotransmitter in 1956. This prompted a search for a GABA analog that would cross the blood-brain barrier for possible therapeutic use. During this search, gamma-hydroxybutyric acid (GHB) was found in the brain and subsequently synthesized in the laboratory in 1964. 1,2 Since its discovery, GHB has
Amino Acids and the Mitochondria
Nicola King
\\u000a This chapter describes some of the important physiological functions of amino acids in the mitochondria and the alterations\\u000a caused by specific pathologies. To some extent all of the featured items are dependent upon the movement of amino acids across\\u000a the highly selective permeability barrier that is the inner mitochondrial membrane. The performance of this transport by specific\\u000a carriers is the
Molecular Structure of Glucuronic acid
NSDL National Science Digital Library
Glucuronic acid is a substance derived from uronic acid, and is found in both plants and animals, usually in combination with phenols or alcohols. It is primarily used in detoxifying drugs and toxins to ensure easy elimination from the body. This substance is soluble in water and alcohol and has a melting point of 165 degrees Celsius. It exhibits mutarotation in the crystal form or its specific rotation of light changes depending on the way the crystals were prepared.
Folic acid and preconceptional care
Nancy H Levine; Katherine Lyon Daniel; Joe Mulinare
If all women capable of becoming pregnant consumed 400 ?g (0.4 mg) of the B vitamin folic acid daily before conception and during the first trimester, the annual number of neural-tube birth defect (NTD)–affected pregnancies in this country could be reduced by 50% to 70%. Despite this important relationship, most women are not aware that folic acid prevents NTDs, and
Factors controlling naphthenic acid corrosion
Turnbull, A. [National Physical Lab., Teddington (United Kingdom); Slavcheva, E. [Bulgarian Academy of Sciences, Sofia (Bulgaria); Shone, B. [Ty Isa, Nr Mold (United Kingdom)
A laboratory study was conducted to elucidate the influence of chemical and physical parameters on corrosion of type 1018 carbon steel (CS, UNS G10180) and 5% Cr-0.5% Mo steel in oils containing naphthenic acids (NAs) for application to crude oil refinery systems. Effects of test duration, temperature, and acid concentration were assessed for a range of single acids of varying carbon numbers and for NA mixtures in mineral oil (MO) and in heavy vacuum gas oil (HGVO). In addition, a limited study of the effect of hydrogen sulfide (H{sub 2}S) addition to the acid-oil mixture was conducted. Use of the total acid number (TAN) as a measure of corrosiveness of a crude oil was discredited further. For the same TAN value, molecular size and structure of the acid were shown to have an important influence. Tests conducted in HGVO showed lower corrosion rates than in MO, suggesting inhibition caused by S species in the oil or the steric hindrance of naphtheno-aromatic acids. In oil containing the mixture of NAs, the corrosion rate of type 1018 CS was lower than that for 5% Cr-0.5% Mo steel. The 0.1% H{sub 2}S that passed through the acid-oil mixtures had an inhibiting effect on corrosion. Predicting corrosiveness of a crude oil from the measurement of TAN, distribution of NA composition, and S content and form was particularly challenging. The simple tests used were informative, but further work will be required to establish a standard test method that can provide an adequate ranking of crudes.
Miroslav Pátek
The branched-chain amino acids (BCAAs) leucine, isoleucine, and valine are synthesized by bacteria,\\u000a fungi, and plants, but are essential for vertebrates including humans, who must receive them from their\\u000a diet. The interest to construct overproducing industrial strains therefore stems from the need to supplement\\u000a the food or feed with these amino acids to use them in medical treatment and as
Hydrothermal synthesis of amino acids
Marshall, W.L. (Oak Ridge National Lab., TN (United States))
This study presents further evidence that amino acids can be synthesized rapidly in hydrothermal solutions from reactants that may have been present in primitive environments. Aqueous NH[sub 4]HCO[sub 3] solutions were reacted with C[sub 2]H[sub 2], H[sub 2], and O[sub 2] (formed in situ from CaC[sub 2], Ca, and H[sub 2]O[sub 2]) at 200-275[degrees]C over 0.2-2 h periods to synthesize several amino acids and abundant amines. These amino acid and amine producing reactions were not observed to occur below 150[degrees]C. Amino acids and amines also were synthesized at 210[degrees]C from solutions of NH[sub 4]OH, HCHO, NaCN, and H[sub 2]. When NH[sub 4]OH was replaced by NH[sub 4]HCO[sub 3], the syntheses predominantly confirmed the recent results of Hennet et al. (1992). Additionally, amino acids and amines were observed to form by reactions among NH[sub 4]OH, HCHO, and H[sub 2] at hydrothermal conditions, essentially confirming the results of Fox and Windsor (1970). Inclusion of both carbonate and O[sub 2] in these latter solutions greatly enhanced the production rate of amino acids. The amines synthesized hydrothermally could be significant if they are precursors in the amino acid syntheses either at hydrothermal or later at lower temperatures. These observations provide additional input to the current questions of synthesis, stability, and decomposition of amino acids at hydrothermal conditions, and their possible relevance to the origin of life.
Molecular Structure of Oxalic acid
NSDL National Science Digital Library
Oxalic acid is an odorless, colorless powder or granular solid. It is used as a scouring agent in textiles for finishing, stripping, cleaning, and as a bleaching agent for stain removal. Oxalic acid is also used as a rust remover as well as a grease and wax removing agent in metal cleaning. It is also used to clean and sterilize equipment, slso as a purifying agent in the pharmaceutical industry, in the waste water treatment industry and is also used to remove calcium from water. Oxalic acid is found in many plants and in many vegetables, for example sorrel, spinach and rhubarb, usually as its calcium or potassium salts. Oxalic acid is produced commercially by nitric acid oxidation of starch. It also can be made by fusing sawdust (or other forms of cellulose) with a mixture of sodium hydroxide and potassium hydroxide. Oxalic acid may be released to the environment in tobacco smoke, automobile exhaust, rendering, in waste streams from pulp bleaching, and by photochemical oxidations of anthropogenic compounds during long range transport.
Conjugated Linoleic Acid Accumulation via 10Hydroxy12-Octadecaenoic Acid during Microaerobic Transformation of Linoleic Acid by Lactobacillus acidophilus
Specific isomers of conjugated linoleic acid (CLA), a fatty acid with potentially beneficial physiological and anticarcinogenic effects, were efficiently produced from linoleic acid by washed cells of Lactobacillus acidophilus AKU 1137 under microaerobic conditions, and the metabolic pathway of CLA production from linoleic acid is explained for the first time. The CLA isomers produced were identified as cis-9, trans-11- or
Growth temperature affects accumulation of exogenous fatty acids and fatty acid composition in Schizosaccharomyces pombe
Virginia M. McDonough; Therese M. Roth
The incorporation of exogenously supplied fatty acids, palmitic acid, palmitoleic acid, oleic acid and linoleic acid, was\\u000a examined in the yeast Schizosaccharomyces pombe at two growth temperatures, 20?C and 30?C. Fatty acids supplied to S. pombe in the growth medium were found to be preferentially incorporated into the cells, becoming a dominant species. The relative\\u000a increase in exogenous fatty acids
Fukiic and piscidic acid esters from the rhizome of Cimicifuga racemosa and the in vitro estrogenic activity of fukinolic acid.
Kruse, S O; Löhning, A; Pauli, G F; Winterhoff, H; Nahrstedt, A
Hydroxycinnamic acid esters of fukiic acid and piscidic acid were isolated from a 50% ethanolic extract obtained from the rhizomes of Cimicifuga racemosa (Ranunculaceae). Besides 2-E-caffeoylfukiic acid (fukinolic acid), 2-E-feruloylfukiic acid (cimicifugic acid A), 2-E-isoferuloylfukiic acid (cimicifugic acid B), 2-E-feruloylpiscidic acid (cimicifugic acid E) and 2-E-isoferuloylpiscidic acid (cimicifugic acid F), free caffeic, ferulic and isoferulic acids were isolated. The estrogenic activity of fukinolic acid was shown by increased proliferation (126% at 5 x 10(-8) M) of an estrogen dependent MCF-7 cell system with reference to estradiol (120% at 10(-10) M). PMID:10630125
Bile acids: regulation of apoptosis by ursodeoxycholic acid
Amaral, Joana D.; Viana, Ricardo J. S.; Ramalho, Rita M.; Steer, Clifford J.; Rodrigues, Cecília M. P.
Bile acids are a group of molecular species of acidic steroids with peculiar physical-chemical and biological characteristics. At high concentrations they become toxic to mammalian cells, and their presence is pertinent in the pathogenesis of several liver diseases and colon cancer. Bile acid cytoxicity has been related to membrane damage, but also to nondetergent effects, such as oxidative stress and apoptosis. Strikingly, hydrophilic ursodeoxycholic acid (UDCA), and its taurine-conjugated form (TUDCA), show profound cytoprotective properties. Indeed, these molecules have been described as potent inhibitors of classic pathways of apoptosis, although their precise mode of action remains to be clarified. UDCA, originally used for cholesterol gallstone dissolution, is currently considered the first choice therapy for several forms of cholestatic syndromes. However, the beneficial effects of both UDCA and TUDCA have been tested in other experimental pathological conditions with deregulated levels of apoptosis, including neurological disorders, such as Alzheimer's, Parkinson's, and Huntington's diseases. Here, we review the role of bile acids in modulating the apoptosis process, emphasizing the anti-apoptotic effects of UDCA and TUDCA, as well as their potential use as novel and alternate therapeutic agents for the treatment of apoptosis-related diseases. PMID:19417220
Biosynthesis of poly(?-glutamic acid) from l -glutamic acid, citric acid, and ammonium sulfate in Bacillus subtilis IFO3335
Masao Kunioka; Atsuo Goto
Poly(?-glutamic acid) (PGA) production in Bacillus subtilis IFO3335 was studied. When l-glutamic acid, citric acid, and ammonium sulfate were used as carbon and nitrogen sources, a large amount of PGA without a by-product such as a polysaccharide was produced. The time courses of cell growth, PGA, glutamic acid, and citric acid concentrations during cultivation were investigated. It was found that
Amyloid-Associated Nucleic Acid Hybridisation
Sebastian Braun; Christine Humphreys; Elizabeth Fraser; Andrea Brancale; Matthias Bochtler; Trevor C. Dale
Nucleic acids promote amyloid formation in diseases including Alzheimer's and Creutzfeldt-Jakob disease. However, it remains unclear whether the close interactions between amyloid and nucleic acid allow nucleic acid secondary structure to play a role in modulating amyloid structure and function. Here we have used a simplified system of short basic peptides with alternating hydrophobic and hydrophilic amino acid residues to
Acid sorption regeneration process using carbon dioxide
King, C. Judson (Kensington, CA); Husson, Scott M. (Anderson, SC)
Carboxylic acids are sorbed from aqueous feedstocks onto a solid adsorbent in the presence of carbon dioxide under pressure. The acids are freed from the sorbent phase by a suitable regeneration method, one of which is treating them with an organic alkylamine solution thus forming an alkylamine-carboxylic acid complex which thermally decomposes to the desired carboxylic acid and the alkylamine.
Fatty Acids Homeostasis; the search for
Knyazev, Andrew
Fatty Acids Homeostasis; the search for the key regulatory factors. --Andrew Knyazev, Math CUStargardt''ss--like macular degenerationlike macular degeneration FA metabolic proteins in diseases #12;FA Homeostasis of the Fatty Acids moleculesFatty Acids molecules !! The mechanism of Fatty Acid homeostasis is not understood
21 CFR 184.1091 - Succinic acid.
Code of Federal Regulations, 2010 CFR
...RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1091 Succinic acid. (a) Succinic acid (C4 H6 O4 , CAS Reg. No. 110-15-6), also referred to as amber acid and ethylenesuccinic acid, is the chemical...
21 CFR 184.1091 - Succinic acid.
Code of Federal Regulations, 2011 CFR
...RECOGNIZED AS SAFE Listing of Specific Substances Affirmed as GRAS § 184.1091 Succinic acid. (a) Succinic acid (C4 H6 O4 , CAS Reg. No. 110-15-6), also referred to as amber acid and ethylenesuccinic acid, is the chemical...
21 CFR 189.155 - Monochloroacetic acid.
Code of Federal Regulations, 2014 CFR
...2014-04-01 2014-04-01 false Monochloroacetic acid. 189.155 Section 189.155 Food and Drugs...Use as Human Food § 189.155 Monochloroacetic acid. (a) Monochloroacetic acid is the chemical chloroacetic acid, C2 H3...
21 CFR 189.155 - Monochloroacetic acid.
Code of Federal Regulations, 2012 CFR
...2012-04-01 2012-04-01 false Monochloroacetic acid. 189.155 Section 189.155 Food and Drugs...Use as Human Food § 189.155 Monochloroacetic acid. (a) Monochloroacetic acid is the chemical chloroacetic acid, C2 H3...
21 CFR 189.155 - Monochloroacetic acid.
Code of Federal Regulations, 2013 CFR
...2013-04-01 2013-04-01 false Monochloroacetic acid. 189.155 Section 189.155 Food and Drugs...Use as Human Food § 189.155 Monochloroacetic acid. (a) Monochloroacetic acid is the chemical chloroacetic acid, C2 H3...
21 CFR 184.1007 - Aconitic acid.
Code of Federal Regulations, 2010 CFR
... 2010-04-01 2009-04-01 true Aconitic acid. 184.1007 Section 184.1007 Food and Drugs...Substances Affirmed as GRAS § 184.1007 Aconitic acid. (a) Aconitic acid (1,2,3-propenetricarboxylic acid (C6...
21 CFR 184.1007 - Aconitic acid.
Code of Federal Regulations, 2011 CFR
...2011-04-01 2011-04-01 false Aconitic acid. 184.1007 Section 184.1007 Food and Drugs...Substances Affirmed as GRAS § 184.1007 Aconitic acid. (a) Aconitic acid (1,2,3-propenetricarboxylic acid (C6...
21 CFR 189.155 - Monochloroacetic acid.
Code of Federal Regulations, 2011 CFR
...2011-04-01 2011-04-01 false Monochloroacetic acid. 189.155 Section 189.155 Food and Drugs...Use as Human Food § 189.155 Monochloroacetic acid. (a) Monochloroacetic acid is the chemical chloroacetic acid, C2 H3...
21 CFR 184.1021 - Benzoic acid.
Code of Federal Regulations, 2011 CFR
... 2011-04-01 2011-04-01 false Benzoic acid. 184.1021 Section 184.1021 Food and Drugs...Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid (C7 H6...
21 CFR 184.1021 - Benzoic acid.
Code of Federal Regulations, 2010 CFR
... 2010-04-01 2009-04-01 true Benzoic acid. 184.1021 Section 184.1021 Food and Drugs...Substances Affirmed as GRAS § 184.1021 Benzoic acid. (a) Benzoic acid is the chemical benzenecarboxylic acid (C7 H6...
21 CFR 189.155 - Monochloroacetic acid.
Code of Federal Regulations, 2010 CFR
...2010-04-01 2009-04-01 true Monochloroacetic acid. 189.155 Section 189.155 Food and Drugs...Use as Human Food § 189.155 Monochloroacetic acid. (a) Monochloroacetic acid is the chemical chloroacetic acid, C2 H3...
Aksay, Ilhan A.
123 ACIDIC BIOPOLYMERS AS DISPERSANTS FOR CERAMIC PROCESSING N. PELLERIN,* J. T. STALEY,* T. REN, University of Washington, Seattle, WA 98195 Some acidic biopolymers serve as dispersantsfor colloidal was reduced by partial acid hydrolysis. Low molecular weight polymers rich in guluronic acid proved
Agronomy Facts 3 Soil Acidity and Aglime
Kaye, Jason P.
Agronomy Facts 3 Soil Acidity and Aglime Summary · Soil pH indicates the acidic level of a soil. A pH less than 7.0 indicates an acid soil. · Soil acidification is a natural process that is increased of soil acidity (low soil pH) can reduce root growth, reduce nutrient availability, and affect crop
Fatty acids for myocardial imaging.
Corbett, J R
Radioiodinated free fatty acids are tracers that can be used to assess both myocardial perfusion and metabolism. There have been several fatty acids and structurally modified fatty acids studied since Evans' initial report of radiolabeled I-123 oleic acid in 1965. The radiolabeling of a phenyl group added to the long chain fatty acids in the omega-terminal position opposite the carboxyl terminal group prevents nonspecific deiodination and the rapid release of free iodine as the tracer undergoes beta-oxidation. The additional inclusion of a methyl or dimethyl group to the chain slows oxidation resulting in prolonged myocardial retention. The longer retention of the radiolabel permits longer image acquisitions more compatible with single photon emission computed tomography (SPECT) imaging, especially with single-detector imaging systems. Several protocols have been implemented using these compounds, particularly 15-(para-iodophenyl)-3-R,S-methyl pentadecanoic BMIPP, to detect abnormal fatty acid metabolism in ischemic heart disease as well as in nonischemic and hypertrophic cardiomyopathies. Successful management of patients with ischemic cardiomyopathies depends on the accurate identification of hibernating myocardium. The studies covered in this review suggest that both IPPA and BMIPP, especially when combined with markers of myocardial perfusion, may be excellent tracers of viable and potentially functional myocardium. Future studies with larger numbers of patients are needed to confirm the results of these studies and to compare their efficacy with that of other available imaging modalities. Cost and distribution issues will have to be resolved for these metabolic tracers to compete in the commercial marketplace. Otherwise they will likely be available only on a limited basis for research use. As progress is made with these issues and with the development of newer imaging systems, the use of radioiodinated and fluorinated fatty acids is likely to be increasingly attractive. PMID:10433339
History of retinoic acid receptors.
Benbrook, Doris M; Chambon, Pierre; Rochette-Egly, Cécile; Asson-Batres, Mary Ann
The discovery of retinoic acid receptors arose from research into how vitamins are essential for life. Early studies indicated that Vitamin A was metabolized into an active factor, retinoic acid (RA), which regulates RNA and protein expression in cells. Each step forward in our understanding of retinoic acid in human health was accomplished by the development and application of new technologies. Development cDNA cloning techniques and discovery of nuclear receptors for steroid hormones provided the basis for identification of two classes of retinoic acid receptors, RARs and RXRs, each of which has three isoforms, ?, ? and ?. DNA manipulation and crystallographic studies revealed that the receptors contain discrete functional domains responsible for binding to DNA, ligands and cofactors. Ligand binding was shown to induce conformational changes in the receptors that cause release of corepressors and recruitment of coactivators to create functional complexes that are bound to consensus promoter DNA sequences called retinoic acid response elements (RAREs) and that cause opening of chromatin and transcription of adjacent genes. Homologous recombination technology allowed the development of mice lacking expression of retinoic acid receptors, individually or in various combinations, which demonstrated that the receptors exhibit vital, but redundant, functions in fetal development and in vision, reproduction, and other functions required for maintenance of adult life. More recent advancements in sequencing and proteomic technologies reveal the complexity of retinoic acid receptor involvement in cellular function through regulation of gene expression and kinase activity. Future directions will require systems biology approaches to decipher how these integrated networks affect human stem cells, health, and disease. PMID:24962878
Hardy, Darel
INTRODUCTION ACID-BASE EQUILIBRIAACID-BASE EQUILIBRIA What are acids and bases? Svante Arrhenius noticed that acids release hy- drogen ions in solution. He classified acids and bases in this way: acids in water to accept a proton. Acids that break up completely in water; these are strong acids. Acids that do
Acid Rain: What It Is -- How You Can Help!
ERIC Educational Resources Information Center
National Wildlife Federation, Washington, DC.
This publication discusses the nature and consequences of acid precipitation (commonly called acid rain). Topic areas include: (1) the chemical nature of acid rain; (2) sources of acid rain; (3) geographic areas where acid rain is a problem; (4) effects of acid rain on lakes; (5) effect of acid rain on vegetation; (6) possible effects of acid rain…
Selective Catalysis of Lactic Acid to Produce Commodity Chemicals
Yongxian Fan; Chunhui Zhou; Xiaohong Zhu
Owning to its biobased organic acid, low cost and multiple reactive functionalities as it contains both one carboxylic acid group and hydroxyl group, lactic acid has been described as a commodity chemical sleeping giant. In this review, the conversion of lactic acid to other important commodity chemicals, such as, poly L?lactic acid, acrylic acid, 2, 3?pentanedione, pyruvic acid, propanoic acid,
Anaerobic biotransformation of organoarsenical pesticides monomethylarsonic acid and dimethylarsinic acid
Sierra-Alvarez, R.; Yenal, U.; Feld, J.A.; Kopplin, M.; Gandolfi, A.J.; Garbarino, J.R.
Monomethylarsonic acid (MMAV) and dimethylarsinic acid (DMAV) are extensively utilized as pesticides, introducing large quantities of arsenic into the environment. Once released into the environment, these organoarsenicals are subject to microbial reactions. Aerobic biodegradation of MMAV and DMAV has been evaluated, but little is known about their fate in anaerobic environments. The objective of this study was to evaluate the biotransformation of MMAV and DMAV in anaerobic sludge. Biologically mediated conversion occurred under methanogenic or sulfate-reducing conditions but not in the presence of nitrate. Monomethylarsonous acid (MMAIII) was consistently observed as an important metabolite of MMAV degradation, and it was recovered in molar yields ranging from 5 to 47%. The main biotransformation product identified from DMAV metabolism was MMAV, which was recovered in molar yields ranging from 8 to 65%. The metabolites indicate that reduction and demethylation are important steps in the anaerobic bioconversion of MMAV and DMAV, respectively. ?? 2006 American Chemical Society.
Naphthenic acids and surrogate naphthenic acids in methanogenic microcosms.
Holowenko, F M; Mackinnon, M D; Fedorak, P M
Naphthenic acids (NAs) are a complex mixture of naturally occurring acyclic and cyclic aliphatic carboxylic acids in petroleum. In the Athabasca oil sands. NAs have been identified as the largest component of dissolved organic matter in the tailings waters from oils sands extraction processes. They are the major contributor to the acute toxicity of the fine tailings wastewaters at the oil sands extraction plants in northeastern Alberta, Canada. In this study, three sources of NAs were studied, including commercially available NAs, those extracted from oil sands process-affected waters, and individual naphthenic-like surrogate compounds. Analysis by gas chromatography-mass spectrometry demonstrated differences between the commercial and extracted NAs. The NAs derived from the process-affected waters showed a short-term inhibition of methanogenesis from H2 or acetate, but with time the populations resumed methane production. It has been postulated that microbial metabolism of the carboxylated side chains of NAs would lead to methane production. The two NA mixtures failed to stimulate methanogenesis in microcosms that contained either oil sands fine tailings or domestic sewage sludge. However, in microcosms with sewage sludge, methanogenesis was stimulated by some surrogate NAs including 3-cyclohexylpropanoic acid at 400-800 mg/L, 5-cyclohexylpentanoic acid at 200 mg/L or 6-phenylhexanoic acid at 200 and 400 mg/L. When added at 200 mg/L to methanogenic microcosms containing fine tailings, 3-cyclohexylpropanoic and 4-cyclohexylbutanoic acids produced methane yields that suggested mineralization of the side chain and the ring. PMID:11456157
Arterial Blood Carbonic Acid Inversely Determines Lactic and Organic Acids
Aiken, Christopher Geoffrey Alexander
Objective: To establish that arterial blood carbonic acid varies inversely with lactic acid in accordance with bicarbonate exchanging for lactate across cell membranes through the anion exchange mechanism to maintain the Gibbs-Donnan equilibrium. Study Design: Over 5 years, lactate was measured on all blood gases taken from neonatal admissions, as well as organic acid whenever electrolytes were required. Results: Arterial blood gases from 63 infants given high calcium TPN were analyzed. Twenty two needed continuous positive airways pressure (CPAP) only and 31 intermittent positive pressure ventilation (IPPV) and surfactant followed by CPAP to treat respiratory distress syndrome in 51 and meconium aspiration syndrome in 2. All survived and were free of infection. Excluded gases were those with high and falling lactate soon after delivery representing perinatal asphyxia, and those on dexamethasone. Strong inverse relations between carbonic and lactic acids were found at all gestational ages and, independent of glomerular filtration, between carbonic and organic acids. Lactate (mmol/L) = 62.53 X PCO2 -0.96(mmHg) r2 0.315, n 1232, p <0.001. Sixty divided by PCO2 is a convenient measure of physiological lactate at any given PCO2. In the first week, 9.13 ± 2.57% of arterial gases from infants on IPPV had lactates above 120/PCO2, significantly more than 4.74 ± 2.73% on CPAP (p<0.05) and 2.47 ± 2.39% on no support. Conclusion: Changes in arterial blood carbonic acid cause immediate inverse changes in lactic acid, because their anions interchange across cell membranes according to the Gibbs –Donnan equilibrium. Increasing PCO2 from 40 to 120 mmHg decreased lactate from 1.5 mmol/L to 0.5 mmol/L, so that the sum of carbonic and lactic acids increased from 2.72 mmol/L to only 4.17 mmol/L. This helps explain the neuroprotective effect of hypercapnoea and highlights the importance of avoiding any degree of hypocapnoea in infants on IPPV. PMID:24392387
Gallic Acid, Ellagic Acid and Pyrogallol Reaction with Metallic Iron
NASA Astrophysics Data System (ADS)
Jaén, J. A.; González, L.; Vargas, A.; Olave, G.
The reaction between gallic acid, ellagic acid and pyrogallol with metallic iron was studied using infrared and Mössbauer spectroscopy. Most hydrolysable tannins with interesting anticorrosive or inhibition properties are structurally related to these compounds, thus they may be used as models for the study of hydrolysable tannins and related polyphenols. The interaction was followed up to 3 months. Results indicated two different behaviors. At polyphenol concentrations higher than 1% iron converts to sparingly soluble and amorphous ferric (and ferrous) polyphenolate complexes. At lower concentrations (0.1%), the hydrolysis reactions are dominant, resulting in the formation of oxyhydroxides, which can be further reduced to compounds like magnetite by the polyphenols.
Acidic properties of aqueous phosphoric acid solutions: a microscopic view.
Harsányi, I; Pusztai, L; Jóvári, P; Beuneu, B
We report on new neutron and x-ray diffraction data on D2O:D3PO4 solutions at two concentrations, 1:1 and 3:1. The experimental datasets were modelled simultaneously by the reverse Monte Carlo (RMC) method. From the resulting models, partial radial distribution functions (prdf) and coordination numbers were obtained. The acidity was found to decrease with increasing D3PO4 concentration. The ratio of dissociated acidic protons was estimated by dedicated simulation runs using average coordination number constraints. It was found that in the saturated solution the ratio of dissociated protons cannot exceed 20%. PMID:24140599
New developments in synthetic fatty acids
Norman O. V. Sonntag
New developments in synthetic fatty acids have occurred in the last few years in Russia, Japan, the United States and Canada.\\u000a In 1959 Russia decided to replace 40% of natural fatty acids in soaps with synthetic fatty acids. In 1966, 548 million pounds\\u000a of C5–C30 synthetic fatty acids were produced including 288 million pounds of C10–C20 fatty acids. Forty million
Identifying a base in a nucleic acid
Fodor, Stephen P. A.; Lipshutz, Robert J.; Huang, Xiaohua
Devices and techniques for hybridization of nucleic acids and for determining the sequence of nucleic acids. Arrays of nucleic acids are formed by techniques, preferably high resolution, light-directed techniques. Positions of hybridization of a target nucleic acid are determined by, e.g., epifluorescence microscopy. Devices and techniques are proposed to determine the sequence of a target nucleic acid more efficiently and more quickly through such synthesis and detection techniques.
Phenol biosynthesis in higher plants. Gallic acid
Dewick, P. M.; Haslam, E.
The biosynthesis of gallic acid in a number of higher plants was investigated by using l-[U-14C]phenylalanine, (?)-[G-14C]shikimic acid, d-[1-14C]glucose and d-[6-14C]glucose as tracers. The results are compared with those obtained similarly for caffeic acid and are interpreted in terms of the dehydrogenation of 5-dehydroshikimic acid as a normal route of metabolism for gallic acid. PMID:5807212
Inhibitors of Fatty Acid Synthesis and Elongation
NSDL National Science Digital Library
Fatty acid synthesis and fatty acid elongation are two parts of a critically important pathway in plants. The endproducts are essential components of cell membranes, waxes, and suberin. Two chemical families of herbicide (groups that share similar chemical structures) inhibit fatty acid synthesis, while fatty acid elongation is inhibited by two other families. This lesson will provide an overview of fatty acid synthesis and elongation, and explain where herbicides inhibit the pathway. Mechanisms of resistance to these herbicides will be described.
Preparation of some amino phosphonic acids
Chambers, James Richard
chloride and sodium hydroxide, rapid stirring was continued for another 30 minutes. This solution was then made acidic to congo red with 6 N hydro? chloric acid, extracted with 13 ml. of diethyl ether to remove unreacted benzoyl chloride and any benzoic... acid is insoluble in ethyl alcohol but its hydrochloride is soluble; therefore, the free acid can be obtained easily by dissolving the hydro? chloride in ethyl alcohol and precipitating the free acid (III) with butene oxide, A 0 + CH...
Gelled acidic well treating composition and process
Swanson, B.L.
Gelled acidic compositions suitable for either matrix-acidizing or fracture-acidizing of subterranean formations comprising water , a water-dispersible polymer selected from cellulose ethers and polymers of acrylamides, an acid, an aldehyde, and a phenolic compound capable of causing gelation of an aqueous dispersion of the polymer, acid, aldehyde, and phenolic compound are provided. In another embodiment, guar gum, polyvinylpyrrolidone and biopolysaccharides can also be used as the polymeric component in said compositions.
Production of arachidonic acid by Mortierella fungi
Yoshifumi Shinmen; Sakayu Shimizu; Kengo Akimoto; Hiroshi Kawashima; Hideaki Yamada
Various Mortierella fungi were assayed for their productivity of arachidonic acid (ARA). Only strains belonging to the subgenus Mortierella accumulated detectable amounts of ARA together with dihomo-?-linolenic acid. None of the strains belonging to the subgenus Micromucor tested accumulated these C-20 fatty acids, although they produced a C-18 fatty acid, ?-linolenic enic acid. A soil isolate, M. alpina 1S-4, was
Polyunsaturated Fatty Acids in Children
Polyunsaturated fatty acids (PUFAs) are the major components of brain and retina, and are the essential fatty acids with important physiologically active functions. Thus, PUFAs should be provided to children, and are very important in the brain growth and development for fetuses, newborn infants, and children. Omega-3 fatty acids decrease coronary artery disease and improve blood flow. PUFAs have been known to have anti-inflammatory action and improved the chronic inflammation such as auto-immune diseases or degenerative neurologic diseases. PUFAs are used for metabolic syndrome related with obesity or diabetes. However, there are several considerations related with intake of PUFAs. Obsession with the intake of unsaturated fatty acids could bring about the shortage of essential fatty acids that are crucial for our body, weaken the immune system, and increase the risk of heart disease, arrhythmia, and stroke. In this review, we discuss types, physiologic mechanism of action of PUFAs, intake of PUFAs for children, recommended intake of PUFAs, and considerations for the intake of PUFAs. PMID:24224148
Amino acids and cell regulation.
Forster, R. P.; Goldstein, L.
Free amino play an important role in regulating cell volume in fishes. Four tissues/cells (skeletal muscle, RBC, brain, and myocardium) of the little skate, Raja erinacea, were selected for detailed study because of their special importance or unique advantage as experimental models. Three particular amino acids, beta-alanine, taurine, and sarcosine play a predominant role in all four tissues. As in higher vertebrates, amino acid uptake in skate brain, heart, and RBC is mediated via a Na+-dependent process. Amino acids leave the skate brain rapidly in response to a sudden decrease in plasma osmolality and/or to a simultaneous drop in extracellular Na+ concentration. However, although amino acids are important for volume regulation in normal brain cells, they do not appear to be likely candidates for the unidentified "idiogenic" osmolytes in mammalian brain cells. The high concentration of taurine in skate myocardium is of special interest because of the special role of this amino acid in myocardial contractility. Thus, unlike beta-alanine and sarcosine, taurine may play a dual role in regulating both cell volume and contractility of myocardial cells. The isolated skate atrium is well suited for in vitro studies of these two processes. PMID:395764
Induction of (+)-abscisic acid 8? hydroxylase by (+)-abscisic acid in cultured maize cells
Adrian J. Cutler; Timothy M. Squires; Mary K. Loewen; John J. Balsevich
In vivo measurements of the enzymatic hydroxylation of the phytohormone (+)-abscisic acid to hormonally inactive (—)-phaseic acid in corn cell cultures revealed that ( + )-abscisic acid 8' hydroxylase activity was induced by (+)-abscisic acid treatment. This induction was blocked by the protein synthesis inhibitor cyclo- heximide and by the transcription inhibitor cordycepin. Following an induction treatment with abscisic acid,
21 CFR 172.350 - Fumaric acid and salts of fumaric acid.
Code of Federal Regulations, 2012 CFR
...2012-04-01 false Fumaric acid and salts of fumaric acid. 172.350 Section...Additives § 172.350 Fumaric acid and salts of fumaric acid. Fumaric acid and its...ferrous, magnesium, potassium, and sodium salts may be safely used in food in...
21 CFR 172.350 - Fumaric acid and salts of fumaric acid.
Code of Federal Regulations, 2014 CFR
...2014-04-01 false Fumaric acid and salts of fumaric acid. 172.350 Section...Additives § 172.350 Fumaric acid and salts of fumaric acid. Fumaric acid and its...ferrous, magnesium, potassium, and sodium salts may be safely used in food in...
21 CFR 172.350 - Fumaric acid and salts of fumaric acid.
Code of Federal Regulations, 2013 CFR
...2013-04-01 false Fumaric acid and salts of fumaric acid. 172.350 Section...Additives § 172.350 Fumaric acid and salts of fumaric acid. Fumaric acid and its...ferrous, magnesium, potassium, and sodium salts may be safely used in food in...
Method of increasing conversion of a fatty acid to its corresponding dicarboxylic acid
Craft, David L.; Wilson, C. Ron; Eirich, Dudley; Zhang, Yeyan
A nucleic acid sequence including a CYP promoter operably linked to nucleic acid encoding a heterologous protein is provided to increase transcription of the nucleic acid. Expression vectors and host cells containing the nucleic acid sequence are also provided. The methods and compositions described herein are especially useful in the production of polycarboxylic acids by yeast cells.
Effect of formic acid and benzoic acid esters on grass preservation
Paris-Sud XI, Université de
Effect of formic acid and benzoic acid esters on grass preservation A Rauramaa A Tommila J Ltd, Espoo Reseach Centre, PO Box 44, 02271 Espoo, Finland Formic acid is known to improve silage hygienic quality. Formic acid based additive containing propionic and benzoic acids inhibits more
21 CFR 172.350 - Fumaric acid and salts of fumaric acid.
Code of Federal Regulations, 2010 CFR
... 2010-04-01 2009-04-01 true Fumaric acid and salts of fumaric acid. 172.350 Section 172.350 Food and Drugs...and Nutritional Additives § 172.350 Fumaric acid and salts of fumaric acid. Fumaric acid...
21 CFR 172.350 - Fumaric acid and salts of fumaric acid.
Code of Federal Regulations, 2011 CFR
... 2011-04-01 2011-04-01 false Fumaric acid and salts of fumaric acid. 172.350 Section 172.350 Food and Drugs...and Nutritional Additives § 172.350 Fumaric acid and salts of fumaric acid. Fumaric acid...
Influence of dietary essential fatty acid level on fatty acid composition in peripheral nerve and muscle
Paris-Sud XI, Université de
Influence of dietary essential fatty acid level on fatty acid composition in peripheral nerve fed with diets containing different levels of essential unsaturated fatty acids, namely linoleic (18 :2 (n-6)) and linolenic (18 : 2 (n-3)) acid, in the oil. Nerve and muscle fatty acids were analyzed
Erythrocyte stearidonic acid and other n-3 fatty acids and CHD in the Physicians' Health Study
Technology Transfer Automated Retrieval System (TEKTRAN)
Intake of marine-based n-3 fatty acids (EPA, docosapentaenoic acid and DHA) is recommended to prevent CHD. Stearidonic acid (SDA), a plant-based n-3 fatty acid, is a precursor of EPA and may be more readily converted to EPA than a-linolenic acid (ALA). While transgenic soyabeans might supply SDA at ...
Citric Acid Passivation of Stainless Steel
NASA Technical Reports Server (NTRS)
Yasensky, David; Reali, John; Larson, Chris; Carl, Chad
Passivation is a process for cleaning and providing corrosion protection for stainless steel. Currently, on Kennedy Space Center (KSC), only parts passivated with nitric acid are acceptable for use. KSC disposes of approximately 125gal of concentrated nitric acid per year, and receives many parts from vendors who must also dispose of used nitric acid. Unfortunately, nitric acid presents health and environmental hazards. As a result, several recent industry studies have examined citric acid as an alternative. Implementing a citric acid-based passivation procedure would improve the health and environmental safety aspects of passivation process. However although there is a lack of published studies that conclusively prove citric acid is a technically sound passivation agent. In 2007, NASA's KSC Materials Advisory Working Group requested the evaluation of citric acid in place of nitric acid for passivation of parts at KSC. United Space Alliance Materials & Processes engineers have developed a three-phase test plan to evaluate citric acid as an alternative to nitric acid on three stainless steels commonly used at KSC: UNS S30400, S41000, and S17400. Phases 1 and 2 will produce an optimized citric acid treatment based on results from atmospheric exposure at NASA's Beach Corrosion Facility. Phase 3 will compare the optimized solution(s) with nitric acid treatments. If the results indicate that citric acid passivates as well or better than nitric acid, NASA intends to approve this method for parts used at the Kennedy Space Center.
Enhancers of iron absorption: ascorbic acid and other organic acids.
Teucher, Birgit; Olivares, Manuel; Cori, Héctor
Ascorbic acid (AA), with its reducing and chelating properties, is the most efficient enhancer of non-heme iron absorption when its stability in the food vehicle is ensured. The number of studies investigating the effect of AA on ferrous sulfate absorption far outweighs that of other iron fortificants. The promotion of iron absorption in the presence of AA is more pronounced in meals containing inhibitors of iron absorption. Meals containing low to medium levels of inhibitors require the addition of AA at a molar ratio of 2:1 (e.g., 20 mg AA: 3 mg iron). To promote absorption in the presence of high levels of inhibitors, AA needs to be added at a molar ratio in excess of 4:1, which may be impractical. The effectiveness of AA in promoting absorption from less soluble compounds, such as ferrous fumarate and elemental iron, requires further investigation. The instability of AA during food processing, storage, and cooking, and the possibility of unwanted sensory changes limits the number of suitable food vehicles for AA, whether used as vitamin fortificant or as an iron enhancer. Suitable vehicles include dry-blended foods, such as complementary, precooked cereal-based infant foods, powdered milk, and other dry beverage products made for reconstitution that are packaged, stored, and prepared in a way that maximizes retention of this vitamin. The consumption of natural sources of Vitamin C (fruits and vegetables) with iron-fortified dry blended foods is also recommended. Encapsulation can mitigate some of the AA losses during processing and storage, but these interventions will also add cost. In addition, the bioavailability of encapsulated iron in the presence/absence of AA will need careful assessment in human clinical trials. The long-term effect of high AA intake on iron status may be less than predicted from single meal studies. The hypothesis that an overall increase of dietary AA intake, or fortification of some foods commonly consumed with the main meal with AA alone, may be as effective as the fortification of the same food vehicle with AA and iron, merits further investigation. This must involve the consideration of practicalities of implementation. To date, programs based on iron and AA fortification of infant formulas and cow's milk provide the strongest evidence for the efficacy of AA fortification. Present results suggest that the effect of organic acids, as measured by in vitro and in vivo methods, is dependent on the source of iron, the type and concentration of organic acid, pH, processing methods, and the food matrix. The iron absorption-enhancing effect of AA is more potent than that of other organic acids due to its ability to reduce ferric to ferrous iron. Based on the limited data available, other organic acids may only be effective at ratios of acid to iron in excess of 100 molar. This would translate into the minimum presence/addition of 1 g citric acid to a meal containing 3 mg iron. Further characterization of the effectiveness of various organic acids in promoting iron absorption is required, in particular with respect to the optimal molar ratio of organic acid to iron, and associated feasibility for food application purposes. The suggested amount of any organic acid required to produce a nutritional benefit will result in unwanted organoleptic changes in most foods, thus limiting its application to a small number of food vehicles (e.g., condiments, beverages). However, fermented foods that already contain high levels of organic acid may be suitable iron fortification vehicles. PMID:15743017
Risk assessment for acid aerosols
Albert, R.E. (Univ. of Cincinnati Medical Center, OH (USA))
The author provides some insights from carcinogen risk assessment that apply to acid aerosols. The greatest need is to understand mechanisms of action as the basis for characterizing dose response relationships at low levels of exposure. Risk assessment is an orderly assembly of the evidence with some agreed upon guidelines as to how to make judgments about the nature (qualitative assessment) and magnitude (quantitative assessment) of health hazards. Risk assessment provides guidance for regulation, but the impetus for regulation comes from public pressure to remedy perceived health problems. There are some sharp contrasts between carcinogens and acid aerosols in terms of risk assessment and management. The regulatory objective for carcinogens is to diminish the tremendous load of cancer mortality as the second leading cause of death. In the case of acid aerosols, the regulatory objective is less pressing: to eliminate mortality among the moribund from heart and pulmonary disease and the prevention of acute impairments of pulmonary function and acute respiratory infections.
Hydroxamic Acids in Asymmetric Synthesis
Li, Zhi; Yamamoto, Hisashi
Metal-catalyzed stereoselective reactions are a central theme in organic chemistry research. In these reactions, the stereoselection is achieved predominantly by introducing chiral ligands at the metal catalyst's center. For decades, researchers have sought better chiral ligands for asymmetric catalysis and have made great progress. Nevertheless, to achieve optimal stereoselectivity and to catalyze new reactions, new chiral ligands are needed. Due to their high metal affinity, hydroxamic acids play major roles across a broad spectrum of fields from biochemistry to metal extraction. Dr. K. Barry Sharpless first revealed their potential as chiral ligands for asymmetric synthesis in 1977: He published the chiral vanadium-hydroxamic-acid-catalyzed, enantioselective epoxidation of allylic alcohols before his discovery of Sharpless Asymmetric Epoxidation, which uses titanium-tartrate complex as the chiral reagent. However, researchers have reported few highly enantioselective reactions using metal-hydroxamic acid as catalysts since then. This Account summarizes our research on metal-catalyzed asymmetric epoxidation using hydroxamic acids as chiral ligands. We designed and synthesized a series of new hydroxamic acids, most notably the C2-symmetric bis-hydroxamic acid (BHA) family. V-BHA-catalyzed epoxidation of allylic and homoallylic alcohols achieved higher activity and stereoselectivity than Sharpless Asymmetric Epoxidation in many cases. Changing the metal species led to a series of unprecedented asymmetric epoxidation reactions, such as (i) single olefins and sulfides with Mo-BHA, (ii) homoallylic and bishomoallylic alcohols with Zr- and Hf-BHA, and (iii) N-alkenyl sulfonamides and N-sulfonyl imines with Hf-BHA. These reactions produce uniquely functionalized chiral epoxides with good yields and enantioselectivities. PMID:23157425
Molecular Structure of Oleic acid
NSDL National Science Digital Library
A mono-unsaturated fatty acid, oleic acid is a component of almost all natural fats. It is obtained from any of various vegetable and animal oils and fats, particularly the seeds of castor, sunflower, safflower, parsley, soybean, flax, perilla, and celery. A colorless or yellow-to-red oily liquid with a lard-like odor, it solidifies to a crystalline mass at four degrees Celsius. When exposed to air it oxidizes and acquires a yellow to brown color and rancid odor; for this reason it should be kept sealed in a container and away from sunlight. It is almost completely insoluble in water but is soluble in alcohol, benzene chloroform, ether, and fixed and volatile oils. Although oleic acid has a low level of toxicity when absorbed orally, it is mildly irritating to the skin and mucous membranes. It also is combustible. Oleic acid is used as a soap base and in the production of food-grade additives, ointments, cosmetics, fragrance products, polishing compounds, surface coatings, and manufacturing driers. It is used for waterproofing textiles and for thickening lubricating oils. It also is used as a solvent in the manufacture of pharmaceuticals. It contributes to the flavor of foods and is found in sweet cider apples. One of the "good" or unsaturated fatty acids, oleic acid has proven helpful to cell and heart function. It has shown anti-inflammatory effects in the body and has been used to treat arthritis, asthma, allergies, and skin conditions. Its inclusion in the diet has improved cases of diabetes, depression, menopausal problems, obesity, memory and learning disabilities, eye problems, and digestive disorders. It is considered to lower the incidence of cancer (as an antioxidant), multiple sclerosis, and lupus as well.
[Uric acid and multiple sclerosis].
Mattle, H P; Lienert, C; Greeve, I
Multiple Sclerosis (MS) is a chronic inflammatory disease of the central nervous system. Its etiology is not known, but it is well established that auto-reactive T-cells and monocytes play an important pathogenetic role. Experimental allergic encephalomyelitis (EAE) of mice serves as disease model for MS. In both EAE and MS inflammatory cells produce nitric oxide and its oxidizing congeners such as peroxynitrite. Peroxynitrite and other reactive nitrogen oxide species exert a toxic effect on neurons, axons and glia cells and enhance apoptosis. In addition, they increase the blood-CNS-barrier permeability and can therefore promote invasion of inflammatory cells into the CNS. On the other hand, uric acid, a peroxynitrite scavenger inhibits blood-CNS-barrier permeability changes, CNS inflammation and tissue damage in EAE. Epidemiological studies have shown that MS and gout are almost mutually exclusive diseases. Uric acid levels in MS patients are lower than in controls and in patients with active disease lower than in MS patients in remission. Inosine, a uric acid precursor, can be used to raise uric acid levels in serum and may provide some benefit in MS patients. A small study of ten patients with progressive MS has demonstrated some improved function in three of them and no sign of progression or relapse in the other. However, this study does not justify a recommendation for use of inosine in MS patients yet. At present, uric acid can solely be regarded as a marker of disease activity in MS. In addition, the current knowledge of uric acid and MS supports hypotheses which predict a positive effect of radical scavengers in MS. PMID:15493114
Identification of nine acetylenic fatty acids, 9-hydroxystearic acid and 9,10-epoxystearic acid in the seed oil of Jodina rhombifolia hook et arn. (Santalaceae)
V. Spitzer; S. A. de L. Bordignon; E. P. Schenkel; F. Marx
In addition to some usual fatty acids, the seed oil ofJodina rhombifolia (Santalaceae) contains nine acetylenic fatty acids [9-octadecynoic acid (stearolic acid) (1.1%),trans-10-heptadecen-8-ynoic acid (pyrulic acid) (20.1%), 7-hydroxy-trans-10-heptadecen-8-ynoic acid (2.3%),trans-10,16-heptadecadien-8-ynoic acid (0.7%), 7-hydroxy-trans-10,16-heptadecadien-8-ynoic acid (0.1%),trans-11-octadecen-9-ynoic acid (ximenynic acid) (20.3%), 8-hydroxy-trans-11-octadecen-9-ynoic acid (12.2%),trans-11,17-octadecadien-9-ynoic acid (1.5%), 8-hydroxy-trans-11,17-octadecadien-9-ynoic acid (1.3%), 9-hydroxystearic acid (<0.1%) and 9,10-epoxystearic acid (0.7%)]. The fatty acids\\u000a have been analyzed
The Nucleic Acid Database (NDB)
NSDL National Science Digital Library
Designed by John Westbrook, and housed at Rutgers University, the goal of the NDB is to assemble and distribute structural information about nucleic acids. The database contains the coordinates of nucleic acid-containing crystal structures, including a searchable atlas of structures, Protein Finder, a search-engine for locating protein structures in the PDB database, a macromolecular crystallographic information file, and archived reports about the structures contained in the database. This site provides information of general interest to researchers in the field, and develops and distributes standard geometry information for use in refinement and molecular modeling programs. Users can also subscribe to the NDB electronic newsletter.
Molecular Structure of (+-)-Malic acid
NSDL National Science Digital Library
Malate, or Malic acid, is found readily in fruits and in the leaves of C4 and CAM plants as storage for carbon dioxide (CO2). In C4 plants, malate is an intermediate during photosynthesis, while in CAM plants it is used to store the CO2 until the stomata are closed at night. It is also key to the production of ATP by the mitochondria. Oxaloacetate is reduced to malate, which is then transported into the mitochondria. Malic acid is frequently used for flavoring of an assortment of products. It is also used as a drug to assist ATP formation, ensuring proper muscle function at even low oxygen levels.
Bipolar lead acid battery development
NASA Technical Reports Server (NTRS)
Eskra, Michael; Vidas, Robin; Miles, Ronald; Halpert, Gerald; Attia, Alan; Perrone, David
A modular bipolar battery configuration is under development at Johnson Control, Inc. (JCI) and the Jet Propulsion Laboratory (JPL). The battery design, incorporating proven lead acid electrochemistry, yields a rechargeable, high-power source that is light weight and compact. This configuration offers advantages in power capability, weight, and volume over conventional monopolar batteries and other battery chemistries. The lead acid bipolar battery operates in a sealed, maintenance-free mode allowing for maximum application flexibility. It is ideal for high-voltage and high-power applications.
Synthesis of some alkylarsonic acids
McBrearty, Charles Francis
of vrhite crystalline product formed. The mixture vias refluxed for an hour prior to fiitnation. The yield of crude n-dodecylansonic acid was 26. 0 g. Several reer ysta I I i zat ions were carried out from acemone-water mixtures un+ i I a constart r.... For the preparation of arsonic acids with carbon cnains longer than n-C additional precautions were found to be necessary in ihe synthesis of the Grignard reagent. A specially constructed three- I0 necked reaction flask (Fig. I & equioped with reflux condenser...
Acidizing of Sandstone Reservoirs Using HF and Organic Acids
Yang, Fei
, and illite) were examined to react with formic-HF acid mixtures which contain different concentrations of HF. Coreflood experiments on sandstone cores featured by different mineralogy with dimensions of 1.5 in. x 6 in. were also conducted at a flow rate of 5...
40 CFR 721.6200 - Fatty acid polyamine condensate, phosphoric acid ester salts.
Code of Federal Regulations, 2010 CFR
...polyamine condensate, phosphoric acid ester salts. 721.6200 Section 721.6200 ...polyamine condensate, phosphoric acid ester salts. (a) Chemical substances and significant...acid polyamine condensate, phosphate ester salts (PMNs P-90-1984 and...
Microbial conversion of 5-sulfoisophthalic acid into 5-hydroxyisophthalic acid by Ochrobactrum anthropi S9.
Yamada, Mamoru; Yoshida, Toyokazu; Nagasawa, Toru
5-Hydroxyisophthalic acid-producing microorganisms were isolated from enrichment cultures using 5-sulfoisophthalic acid as a sulfur source. One bacterium, Ochrobactrum anthropi S9, had the highest 5-sulfoisophthalic acid-degrading activity, and stoichiometrically formed 5-hydroxyisophthalic acid, a raw material for polymer synthesis. Under optimum culture conditions, 1.3 mM 5-hydroxyisophthalic acid accumulated in the medium by 60 h. The addition of Na(2)SO(4), L: -methionine or L: -cysteine at 2 mM inhibited the conversion of 5-sulfoisophthalic acid. O. anthropi S9 cells converted 5-sulfoisophthalic acid, benzenesulfonic acid, 3-sulfobenzoic acid, 4-aminobenzenesulfonic acid, naphthalene-1-sulfonic acid and naphthalene-2-sulfonic acid into the corresponding hydroxylated compounds. PMID:19941033
40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...
Code of Federal Regulations, 2014 CFR
... 2014-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...
40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.
Code of Federal Regulations, 2012 CFR
...2012-07-01 2012-07-01 false Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane. 721.10109 Section...Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed triesters with...
40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.
Code of Federal Regulations, 2013 CFR
...2013-07-01 2013-07-01 false Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane. 721.10109 Section...Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed triesters with...
40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...
Code of Federal Regulations, 2012 CFR
... 2012-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...
40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...
Code of Federal Regulations, 2013 CFR
... 2013-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...
A method for concentrating and analyzing acidic trace organics produced by the chlorination of humic acids at concentrations approximating common drinking water levels is described. Data are compared from several humic acid sources. Specific compound analyses of the extracts were...
46 CFR 151.50-77 - Fluorosilicic acid (30% or less) (hydrofluorosilicic acid).
Code of Federal Regulations, 2011 CFR
...2011-10-01 2011-10-01 false Fluorosilicic acid (30% or less) (hydrofluorosilicic acid). 151.50-77 Section 151.50-77...Requirements § 151.50-77 Fluorosilicic acid (30% or less) (hydrofluorosilicic...
40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.
Code of Federal Regulations, 2010 CFR
...2010-07-01 2010-07-01 false Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane. 721.10109 Section...Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed triesters with...
46 CFR 151.50-77 - Fluorosilicic acid (30% or less) (hydrofluorosilicic acid).
Code of Federal Regulations, 2010 CFR
...2010-10-01 2010-10-01 false Fluorosilicic acid (30% or less) (hydrofluorosilicic acid). 151.50-77 Section 151.50-77...Requirements § 151.50-77 Fluorosilicic acid (30% or less) (hydrofluorosilicic...
40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...
Code of Federal Regulations, 2010 CFR
... 2010-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...
40 CFR 721.10109 - Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane.
Code of Federal Regulations, 2011 CFR
...2011-07-01 2011-07-01 false Hexanoic acid, 2-ethyl-, mixed triesters with benzoic acid and trimethylolpropane. 721.10109 Section...Chemical Substances § 721.10109 Hexanoic acid, 2-ethyl-, mixed triesters with...
40 CFR 721.10125 - Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid...
Code of Federal Regulations, 2011 CFR
... 2011-07-01 false Alkenedioic acid, dialkyl ester, reaction products with polyaminocarbomonocycle and alkenoic acid alkyl ester (generic). 721.10125...Substances § 721.10125 Alkenedioic acid, dialkyl ester, reaction products...
Detoxification of ferulic acid by ectomycorrhizal fungi.
Münzenberger, B; Hammer, E; Wray, V; Schauer, F; Schmidt, J; Strack, D
The ectomycorrhizal fungi Laccaria amethystina and Lactarius deterrimus grown in liquid culture were used to study the fate of added ferulic acid. Laccaria amethystina degraded ferulic acid to the major metabolite vanillic acid. The intermediate vanillin was not detected. Lactarius deterrimus showed a completely different detoxification pattern. Two dimers and one trimer of ferulic acid could be identified as polymerization products of this fungus. A bioassay of the possible biological activities of ferulic acid and vanillic acid on these fungi revealed that vanillic acid was less toxic than ferulic acid for Laccaria amethystina but that both phenolic acids were toxic for Lactarius deterrimus. The results are discussed with respect to ectomycorrhizal fungal growth in the organic layer of forest soils and between living root cells of ectomycorrhizas. PMID:12682834
The occurrence and significance of Campylobacter jejuni in man and animals
S. M. Shane; M. S. Montrose
Campylobacter jejuni, which is now recognized as a discrete species, is a gram negative, microaerophilic, thermophilic, nalidixic acid sensitive, hippurate positive pathogen requiring special selective media for propogation. The organism is widely distributed in avian species, experimental and companion animals and in humans. Mammalian campylobacteriosis is characterized by an enterocolitis of variable severity. The prevalence of the condition is relatively
Monitoring of workers exposed to a mixture of toluene, styrene and methanol vapours by means of diffusive air sampling, blood analysis and urinalysis
Toshio Kawai; Tomojiro Yasugi; Kazunori Mizunuma; Shun'ichi Horiguchi; Ikuharu Morioka; Kazuhisa Miyashita; Yoko Uchida; Masayuki Ikeda
Summary Exposure of 34 male workers to combined toluene, styrene and methanol was monitored by personal diffusive sampling of solvent vapours in breathing zone air, analysis of shift-end blood for the 3 solvents and analysis of shift-end urine for hippuric, mandelic and phenylglyoxylic acids and methanol. The exposure of most of the workers was below current occupational exposure limits. Regression
The utilization of tricarboxylic acid cycle acids and the uptake of succinic acid by Neurospora crassa
Gilliland, Patti Lynn
to 20 140 pH 4. 1 25 C pH 7. 0 g 120 F100 I ~sc E ef 80 Z V lJ ul 40 0 p 40 2 Z 3'C 20 0 0 5 10 15 20 0 5 10 15 20 TIME, minutes Figure 2. Effect of Temperature on Uptake and Accumulation of Succinic Acid. External concentration... of Succinic Acid on Intracellular Concentration of Succinic Acid After 15 Minutes. 32 Id pH 4. 1 pH 1. 0 140 CONTROL 4 CONTROL e 120 V SUFFER 100 4 V V S0 Z V V 0 $ 40 Z 20 / . 7 / js I 4 e SUFFER I. / I 0 5 10 'IS 20 0 S 10 15 20...
Bioconversion of fumaric acid to succinic acid by recombinant E. coli
Xiaohai Wang; C. S. Gong; George T. Tsao
Succinic acid was produced efficiently from fumaric acid by a recombinantE. coli strain DH5?t\\/pGC1002 containing multicopy fumarate reductase genes. The effects of initial fumaric acid and glucose concentration\\u000a on the production of succinic acid were investigated. Succinic acid reached 41 to over 60 g\\/L in 48.5 h starting with 50 to\\u000a 64 g\\/L fumaric acid. Significant substrate inhibition was observed
Role of oleic acid in the metabolism of essential fatty acids
G. A. Dhopeshwarkar; James F. Mead
Groups of young male guinea pigs were fed diets containing corn oil, coconut oil, coconut oil plus elaidic acid, and coconut\\u000a oil plus oleic acid. The oleic acid-fed group showed signs of essential fatty acid deficiency after four weeks and severe\\u000a signs after eight weeks. The elaidic acid-fed group did not show these symptoms. It is proposed that oleic acid
Incorporation and distribution of dihomo-gamma-linolenic acid, arachidonic acid, and eicosapentaenoic acid in cultured human keratinocytes
Punnonen, K.; Puustinen, T.; Jansen, C.T.
Human keratinocytes in culture were labelled with /sup 14/C-dihomo-gamma-linolenic acid, /sup 14/C-arachidonic acid or /sup 14/C-eicosapentaenoic acid. All three eicosanoid precursor fatty acids were effectively incorporated into the cells. In phospholipids most of the radioactivity was recovered, in neutral lipids a substantial amount, and as free unesterified fatty acids only a minor amount. Most of the radioactivity was found in phosphatidylethanolamine which was also the major phospholipid as measured by phosphorous assay. The incorporation of dihomo-gamma-linolenic acid and arachidonic acid into lipid subfractions was essentially similar. Eicosapentaenoic acid was, however, much less effectively incorporated into phosphatidylinositol + phosphatidylserine and, correspondingly, more effectively into triacylglycerols as compared to the two other precursor fatty acids. Once incorporated, the distribution of all three precursor fatty acids was relatively stable, and only minor amounts of fatty acids were released into the culture medium during short term culture (two days). Our study demonstrates that eicosanoid precursor fatty acids are avidly taken up by human keratinocytes and esterified into membrane lipids. The clinical implication of this finding is that dietary manipulations might be employed to cause changes in the fatty acid composition of keratinocytes.
Fatty Acid Based Biodegradable Polymer
Jay Prakash Jain; Marina Sokolsky; Neeraj Kumar; A. J. Domb
Synthetic polymers have become an indispensable part of the daily?life of human beings and the biodegradable class of polymers hold immense value in therapeutics. Fatty acid incorporation in biodegradable polymers renders flexibility, low melting point, hydrophobicity, and pliability properties. At the same time, degradation into naturally occurring compounds makes them environmentally friendly besides their utility in various applications like drug
Solution properties of polygalacturonic acid
Stoddart, R. W.; Spires, I. P. C.; Tipton, K. F.
1. The specimen of polygalacturonic acid used in these studies was shown to contain very little neutral sugar, methyl ester groups or ash, and only residues of galacturonic acid. Its electrophoretic homogeneity was examined in pyridine–acetic acid buffer at pH6·5 and in borate buffer at pH9·2. The distribution of effective particle weights was shown to be fairly narrow. 2. The pH-titration curve of the polymer gave a pK value of 3·7. 3. The interaction of the polymer with Ruthenium Red was studied and titration curves were obtained for the spectral shifts associated with the formation of a complex. 4. Optical-rotatory-dispersion studies showed that the Drude constant, ?c, was dependent on pH. 5. Polygalacturonic acid was shown to display non-Newtonian properties in solution and to have an anomalously high relative specific viscosity at low concentrations. 6. Studies were made of the pH-dependence of the sedimentation coefficient of the polymer. 7. These results are discussed in terms of the structure of the molecule and their relevance to the properties of pectic substances. PMID:5343801
Oxidative stability of fatty acids
Technology Transfer Automated Retrieval System (TEKTRAN)
The use of polyunsaturated fatty acids in poultry feeds follows the recent trend in the food industry to fortify processed foods with health promoting supplements. The chemical structure of these compounds presents a challenge to the feed formulator and producer that must contend with such unstable ...
Catalytic Ozonation of Sulfosalicylic Acid
Tong Shao Ping; Leng Wen Hua; Zhang Jian Qing; Cao Chu Nan
The investigation of heterogeneous catalytic ozonation of sulfosalicylic acid (SSal) in aqueous solution is reported in this paper. It was found that catalytic ozonation in the presence of V-O supported on silica gel had a more positive effect on the removal rate (62% in 30 min) of total organic carbon (TOC) than that of ozonation alone (20% in 30 min),
Folic Acid Questions and Answers
... Multimedia & Tools Partners About Us Information For... Media Policy Makers Questions and Answers Language: English Espańol (Spanish) Recommend on Facebook Tweet Share Compartir Q: Why can't I wait until I'm pregnant—or planning to get pregnant to start taking folic acid? ...
Total synthesis of lysergic acid.
Umezaki, Satoshi; Yokoshima, Satoshi; Fukuyama, Tohru
A total synthesis of lysergic acid was accomplished. Key features of our synthesis include stereoselective construction of the stereogenic centers at the allylic positions by using the Evans aldol reaction, and a sequential process with a ring-closing metathesis and an intramolecular Heck reaction to construct the C and D rings. PMID:23919892
Combinatorics of aliphatic amino acids
NASA Astrophysics Data System (ADS)
Grützmann, Konrad; Böcker, Sebastian; Schuster, Stefan
This study combines biology and mathematics, showing that a relatively simple question from molecular biology can lead to complicated mathematics. The question is how to calculate the number of theoretically possible aliphatic amino acids as a function of the number of carbon atoms in the side chain. The presented calculation is based on earlier results from theoretical chemistry concerning alkyl compounds. Mathematical properties of this number series are highlighted. We discuss which of the theoretically possible structures really occur in living organisms, such as leucine and isoleucine with a chain length of four. This is done both for a strict definition of aliphatic amino acids only involving carbon and hydrogen atoms in their side chain and for a less strict definition allowing sulphur, nitrogen and oxygen atoms. While the main focus is on proteinogenic amino acids, we also give several examples of non-proteinogenic aliphatic amino acids, playing a role, for instance, in signalling. The results are in agreement with a general phenomenon found in biology: Usually, only a small number of molecules are chosen as building blocks to assemble an inconceivable number of different macromolecules as proteins. Thus, natural biological complexity arises from the multifarious combination of building blocks.
Cell biology of polysialic acid
Jozsef Zoltán Kiss; Genevičve Rougon
The unusual carbohydrate polysialic acid (PSA), attached uniquely to neural cell adhesion molecule (NCAM) through a developmentally regulated process, modulates neural cell interactions. Major advances in the past two years have increased our understanding of PSA biosynthesis and regulation. Of particular interest is the cloning of the genes encoding polysialyltransferases (PSTs) and the finding that a single enzyme is able
Getting folic acid nutrition right
Technology Transfer Automated Retrieval System (TEKTRAN)
The two articles in this issue of the journal provide some definitive answers to questions relating to folic acid exposure and folate nutritional status of the US population in the post-fortification era, and, by implication, pose other questions. Most convincingly, these reports, which are based la...
Boric Acid in Kjeldahl Analysis
ERIC Educational Resources Information Center
Cruz, Gregorio
The use of boric acid in the Kjeldahl determination of nitrogen is a variant of the original method widely applied in many laboratories all over the world. Its use is recommended by control organizations such as ISO, IDF, and EPA because it yields reliable and accurate results. However, the chemical principles the method is based on are not…
Trichloroacetic acid (TCA)is a by-product of the chlorine disinfection of water containing natural organic material. It is detectable finished drinking water at levels comparable to the trihalomethanes (30-60). TCA is also formed in vivo after ingestion of hypochlorite and has be...
Hydrogenation using hydrides and acid
Bullock, R. Morris (Wading River, NY)
A process for the non-catalytic hydrogenation of organic compounds, which contain at least one reducible functional group, which comprises reacting the organic compound, a hydride complex, preferably a transition metal hydride complex or an organosilane, and a strong acid in a liquid phase.
Toxicological characterization of phthalic Acid.
Bang, Du Yeon; Lee, In Kyung; Lee, Byung-Mu
There has been growing concern about the toxicity of phthalate esters. Phthalate esters are being used widely for the production of perfume, nail varnish, hairsprays and other personal/cosmetic uses. Recently, exposure to phthalates has been assessed by analyzing urine for their metabolites. The parent phthalate is rapidly metabolized to its monoester (the active metabolite) and also glucuronidated, then excreted. The objective of this study is to evaluate the toxicity of phthalic acid (PA), which is the final common metabolic form of phthalic acid esters (PAEs). The individual PA isomers are extensively employed in the synthesis of synthetic agents, for example isophthalic acid (IPA), and terephthalic acid (TPA), which have very broad applications in the preparation of phthalate ester plasticizers and components of polyester fiber, film and fabricated items. There is a broad potential for exposure by industrial workers during the manufacturing process and by the general public (via vehicle exhausts, consumer products, etc). This review suggests that PA shows in vitro and in vivo toxicity (mutagenicity, developmental toxicity, reproductive toxicity, etc.). In addition, PA seems to be a useful biomarker for multiple exposure to PAEs in humans. PMID:24278572
This report documents the discussions and results of the U.S. Environmental Protection Agency's (EPA's) Acid Aerosol Measurement Method intercomparison Workshop, held April 10-11, 1991 in Research Triangle Park, NC. he workshop was designed to achieve two objectives: (1) to repor...
The acid rain problem is a controversial subject that encompasses scientific, economic, and political issues. Despite the numerous popular articles, technical meetings, and large sums of money spent for research, we seem to be no closer to a solution of the problem than we were a...
Volker A. Mohnen
Acid rain's effects in soil and water leave no doubt about the need to control its causes. The main culprits are sulfur dioxide and nitrogen oxides, mainly from automobiles and power plants. This paper explains the extent of the problem in the USA. This paper also discusses environmentally and economically attractive technologies for the control of these pollutants: atmospheric fluidized
Acid deposition: a national problem
Hendrey, G.R.
The deposition of excessive quantities of sulfur and nitrogen from the atmosphere constitutes a problem encompassing all of the United States east of the Mississippi River. It also occurs in some areas of the western US. Calculations based on emission inventories and simplifying assumptions indicate electric utilities account for 66% of SO/sub 2/ emissions, 29% of NO/sub x/ emissions and about half of precipitation acidity. Acidification of clearwater lakes and streams is a widespread problem only in areas receiving rain with an average acidity less than or equal to 4.7. The dominant anion in such waters is SO/sub 4//sup 2 -/ and concentrations of aluminum derived from watershed acidification may exceed 200 ..mu..g 1/sup -1/. Changes in assemblages of aquatic biota become increasingly apparent as pH decreases below 6.0, and elimination of fish from some waters has been documented. The sensitivity of surface waters is controlled by and represents an integration of biogeochemical processes in their edaphic settings. Changes in surface water chemistry imply changes in the terrestrial environment. Direct evidence of changes in terrestrial environments is sparse. Nevertheless, observations of forest dieback in the US and abroad suggest that acid deposition may contribute to the problem. Very few credible studies are available which allow an evaluation of acid precipitation effects on crops.
Photosensitized degradation of folic acid
NASA Astrophysics Data System (ADS)
Vorobei, A. V.; Vorobei, P. A.
We demonstrate the key role of singlet oxygen in photodegradation of folic acid on exposure to UVA radiation and with photosensitizing treatment. We propose possible uses for photosensitized degradation of folates to enhance the efficacy of photodynamic therapy and for development of a high-sensitivity photochemical method for determining folates in biological systems.
Applications of peptide nucleic acids
Peter E Nielsen
Several exciting new developments in the applications of the DNA mimic peptide nucleic acid (PNA) have been published recently. A possible breakthrough may have come in efforts to develop PNA into gene therapeutic drugs. In eukaryotic systems, antisense activity of PNAs (as peptide conjugates) has been reported in nerve cells and even in rats upon injection into the brain, and
Compositions for acid treating subterranean formations
Clark, E. Jr.; Swanson, B.L.
This patent describes a high viscosity acid composition. It comprises: an aqueous acid solution; one or more acrylamide polymers dissolved in the acid solution in an amount sufficient to increase the viscosity of the acid solution; a liquid hydrocarbon dispersed in the acid solution; and one or more nonionic surface active agents having at least one reactive hydroxyl group per molecule present in the composition in an amount sufficient to interact with the acrylamide polymer or polymers in the presence of the liquid hydrocarbon whereby the viscosity of the acid solution is further increased and stabilized.
Nitric acid uptake by sulfuric acid solutions under stratospheric conditions - Determination of Henry's Law solubility
NASA Technical Reports Server (NTRS)
Reihs, Christa M.; Golden, David M.; Tolbert, Margaret A.
The uptake of nitric acid by sulfuric acid solutions representative of stratospheric particulate at low temperatures was measured to determine the solubility of nitric acid in sulfuric acid solutions as a function of H2SO4 concentration and solution temperature. Solubilities are reported for sulfuric acid solutions ranging from 58 to 87 wt pct H2SO4 over a temperature range from 188 to 240 K, showing that, in general, the solubility of nitric acid increases with decreasing sulfuric acid concentration and with decreasing temperature. The measured solubilities indicate that nitric acid in the global stratosphere will be found predominantly in the gas phase.
Chicoric Acid Found in Basil (Ocimum basilicum L.) Leaves
Technology Transfer Automated Retrieval System (TEKTRAN)
This is the first report to identify the presence of chicoric acid (cichoric acid; also known as dicaffeoyltartaric acid) in basil leaves. Rosmarinic acid, chicoric acid, and caftaric acid (in the order of most abundant to least; all derivatives of caffeic acid) were identified in fresh basil leaves...
Interaction of cellulase with three phenolic acids.
Tian, Ye; Jiang, Yue; Ou, Shiyi
The activity of cellulase against filter paper was enhanced by 28.32% and 15.17% after the addition of 0.83 mg/ml of ferulic acid and p-coumaric acid, respectively, and by 10.15% after the addition of salicylic acid at 0.67 mg/ml. The effects of three phenolic acids on the structure of cellulase were investigated via ultraviolet spectrophotometry, fluorescence spectroscopy, and circular dichroism (CD) spectroscopy. Ultraviolet spectroscopic results indicated that the peak absorbance of cellulase significantly increased and exhibited a 4-5 nm redshift after the addition of the three phenolic acids, suggesting that the phenolic acids strongly interacted with the enzyme. Fluorescence investigation of the interaction between the enzyme and the phenolic acids showed that ferulic acid and p-coumaric acid covalently reacted with the aromatic amino acid residues in cellulase, whereas salicylic acid interacted non-covalently with cellulase. CD analysis revealed that the addition of the phenolic acids significantly decreased ?-helix content but increased ?-sheet and random coil contents. The possible mechanism underlying the effects of these phenolic acids on cellulase activity was also discussed. PMID:23411209
Kinetics and Products of Heterogeneous Oxidation of Oleic acid, Linoleic acid and Linolenic acid in Aerosol Particles by Hydroxyl radicals
T. Nah; S. R. Leone; K. R. Wilson
A significant mass fraction of atmospheric aerosols is composed of a variety of oxidized organic compounds with varying functional groups that may affect the rate at which they chemically age. Here we study the heterogeneous reaction of OH radicals with different sub-micron, alkenoic acid particles: Oleic acid (OA), Linoleic acid (LA), and Linolenic acid (LNA), in the presence of H2O2
Biological Control of Phytopathogenic Fungi by Fatty Acids
Siyun Liu; Weibin Ruan; Jing Li; Hua Xu; Jingan Wang; Yubao Gao; Jingguo Wang
The aim of the present study was to evaluate the antifungal activity of fatty acids against phytopathogenic fungi. Two pot\\u000a experiments were conducted by mixing palmitic and oleic acids in the soil in which poor plant growth was observed. In addition,\\u000a the antifungal activities of nine fatty acids (butyric acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic\\u000a acid,
Transformation of chenodeoxycholic acid to ursodeoxycholic acid in patients with Crohn's disease
Miwa, H.; Yamamoto, M.; Nishida, T.; Yao, T.
In vivo 7 beta-epimerization of chenodeoxycholic acid to ursodeoxycholic acid and the role of 7-ketolithocholic acid as an intermediate in this biotransformation were studied in 11 patients with Crohn's disease and in 5 healthy volunteers. The incorporation of deuterium into biliary ursodeoxycholic acid and 7-ketolithocholic acid was determined by computed gas chromatography-mass fragmentography after ingestion of a dideuterated chenodeoxycholic acid, chenodeoxycholic-11,12-d2 acid. The incorporation of deuterium into ursodeoxycholic acid increased to a peak level at 48 h in the patients with Crohn's disease, but was delayed in healthy volunteers. In 8 patients and 2 healthy controls there were small amounts of 7-ketolithocholic acid in bile. The incorporation of deuterium into 7-ketolithocholic acid was confirmed in only 2 patients and the peak level was noted at 48 h. These observations suggest that 7-ketolithocholic acid is an intermediate of this biotransformation in patients with Crohn's disease.
Determination of fumaric acid, maleic acid, and phthalic acid in groundwater and soil
Dietz, E.A.; Singley, K.F. (Occidental Chemical Corp., Grand Island, NY (United States). Technology Center)
When present at > 1 [mu]g/mL, each title compound was determined in groundwater by ion-exclusion chromatography after sample acidification and filtration. For groundwater with one or all analyte concentrations of < 1 [mu]g/mL, the acid anions were first concentrated from a 100-mL sample using a quaternary amine anion-exchange cartridge. The acids were recovered by eluting the cartridge with 1 mL of N H[sub 2]SO[sub 4] and 2-mL deionized water washes; this solution then was examined by anion-exclusion chromatography. Analytes were monitored with a UV detector operated at 200 nm. The analysis procedures for groundwater were validated with solutions which were fortified with from 50 ng/mL to 200 [mu]g/mL of each analyte; recoveries ranged from 90 to 110%. The soil method was validated using fortified samples which contained each acid at concentrations of from 5 to 160 [mu]g/g. Recovery values were between 81 and 120%. For samples exhibiting minimal detector response from compounds other than the acids of interest, 100-[mu]L injection volumes provided an estimated detection limit of 1 [mu]g/g for soil and 10 ng/mL for groundwater.
Generation of nitric oxide and possibly nitroxyl by nitrosation of sulfohydroxamic acids and hydroxamic acids.
Shirota, F N; DeMaster, E G; Lee, M J; Nagasawa, H T
Diazeniumdiolates (NONOates) and sulfohydroxamic acids are chemical entities that spontaneously generate nitric oxide (NO) and nitroxyl (HNO), respectively, at physiological pH and temperature. By combining the functional aspects of the NONOates with the hydroxamic acids and sulfohydroxamic acids, hybrid NONOate-type compounds that could theoretically generate nitroxyl or nitric oxide can be rationalized. Although the instability of these compounds, viz., the N-nitrosohydroxamic acids and the N-nitrososulfohydroxamic acids, precluded their chemical characterization by actual isolation, their transient existence was deduced by identification of the products of their decomposition. Thus, treatment of benzohydroxamic acid (BHA) with limiting or excess nitrous acid (from NaNO(2) and H(3)PO(4)) gave rise to quantitative generation of N(2)O, possibly via HNO, based on the limiting reactant. Nitrosation of N-t-butyloxycarbonyl hydroxylamine gave similar results. The organic acid produced from BHA was identified as benzoic acid. No nitric oxide was detected from these reactions. In contrast, treatment of Piloty's acid (benzenesulfohydroxamic acid) and methanesulfohydroxamic acid (MSHA) with nitrous acid under the same conditions as above gave 36% of the theoretical quantity of NO from Piloty's acid and 47% of NO from MSHA, although finite quantities of HNO (measured as N(2)O) were also formed. The organic acid produced from Piloty's acid was identified by reverse-phase HPLC as the redox product, benzenesulfinic acid. PMID:10637122
Bile acids: the role of peroxisomes
Ferdinandusse, Sacha; Denis, Simone; Faust, Phyllis L.; Wanders, Ronald J. A.
It is well established that peroxisomes play a crucial role in de novo bile acid synthesis. Studies in patients with a peroxisomal disorder have been indispensable for the elucidation of the precise role of peroxisomes. Several peroxisomal disorders are associated with distinct bile acid abnormalities and each disorder has a characteristic pattern of abnormal bile acids that accumulate, which is often used for diagnostic purposes. The patients have also been important for determining the pathophysiological consequences of defects in bile acid biosynthesis. In this review, we will discuss all the peroxisomal steps involved in bile acid synthesis and the bile acid abnormalities in patients with peroxisomal disorders. We will show the results of bile acid measurements in several tissues from patients, including brain, and we will discuss the toxicity and the pathological effects of the abnormal bile acids. PMID:19357427
Perfluoroalkyl acids (PFAA) such as perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS),and fluorotelomer alcoholsare surfactants that have wide applications in industrial and consumer products. Various fluorotelomer alcohols are known to be metabolized to perfluo...
Serum bile acids in companion animal medicine.
Center, S A
Quantification of total serum bile acids is used as a method for appraising liver function and perfusion in contemporary small animal practice. This article provides a historical perspective and a comprehensive review of bile acid physiology, laboratory methodologies for bile acid quantification, and normal values published for total serum bile acids measured using the spectrophotometric enzymatic method and for serum bile acids measured using validated radioimmunoassay procedures. The variables influencing the enterohepatic circulation of bile acids and, consequently, the fasting and postprandial serum bile acid concentrations are discussed with the intent of clarifying the application of test results to clinical patients. A brief discussion of the therapeutic use of dehydrocholate and ursodeoxycholic acid in clinical patients is provided. PMID:8503164
Retinoids are teratogenic in humans and animals, producing a syndrome of craniofacial malformations which includes cleft palate. his study investigates the mechanism through which retinoic acid induces cleft palate. urine palatogenesis after exposure to retinoic acid in utero is ...
Acids aided by microemulsions increase permeability
Gardner, T.R.; Wood, F. (Halliburton Services, Duncan, OK (US))
This article reports how, in more than 200 acid stimulation jobs recently performed on Kansas wells, operators have gained up to fourfold production increases by incorporating microemulsions into their acid treatments. Most of the 200 wells so treated had already been acidized conventionally, yielding disappointing results. The effect of properly formulated microemulsions on acid stimulation solutions is to allow the acid to sweep oil through pore spaces to penetrate further into formation rock at lower injection pressure. Deeper penetration with live acid consequently results in permeability increases for more formation area. Microemulsion systems (MES) also aid in faster cleanup of acidizing fluids since the MES reduces crude oil saturation in the near-well bore area; relative permeability is thus increased and water-based acid treatment moves more freely through the formation.
21 CFR 172.130 - Dehydroacetic acid.
Code of Federal Regulations, 2011 CFR
...following specifications: Dehydroacetic acid: Melting point, 109 °C-111 °C; assay, minimum 98 percent (dry basis). Sodium salt of dehydroacetic acid: Assay, minimum 98 percent (dry basis). (b) It is used or...
21 CFR 172.130 - Dehydroacetic acid.
Code of Federal Regulations, 2012 CFR
...following specifications: Dehydroacetic acid: Melting point, 109 °C-111 °C; assay, minimum 98 percent (dry basis). Sodium salt of dehydroacetic acid: Assay, minimum 98 percent (dry basis). (b) It is used or...
21 CFR 172.130 - Dehydroacetic acid.
Code of Federal Regulations, 2014 CFR
...following specifications: Dehydroacetic acid: Melting point, 109 °C-111 °C; assay, minimum 98 percent (dry basis). Sodium salt of dehydroacetic acid: Assay, minimum 98 percent (dry basis). (b) It is used or...
21 CFR 172.130 - Dehydroacetic acid.
Code of Federal Regulations, 2010 CFR
...following specifications: Dehydroacetic acid: Melting point, 109 °C-111 °C; assay, minimum 98 percent (dry basis). Sodium salt of dehydroacetic acid: Assay, minimum 98 percent (dry basis). (b) It is used or...
21 CFR 172.130 - Dehydroacetic acid.
Code of Federal Regulations, 2013 CFR
...following specifications: Dehydroacetic acid: Melting point, 109 °C-111 °C; assay, minimum 98 percent (dry basis). Sodium salt of dehydroacetic acid: Assay, minimum 98 percent (dry basis). (b) It is used or...
Acetic Acid Off Gassing in Clamshell Enclosures
Brewer, Allison
. This presentation will investigate the use of acid detection strips (A-D strips) to study acetic acid off gassing occurring in custom-made, cloth covered book boxes constructed and used by conservators in research libraries....
Chronic boric acid poisoning in infants
K OSullivan; M Taylor
We report 7 infants suffering from seizures induced by chronic boric acid ingestion. The boric acid was given by dipping a soother in a proprietary borax and honey mixture. The babies have remained well since the mixture was withheld.
Replica amplification of nucleic acid arrays
Church, George M. (Brookline, MA)
A method of producing a plurality of a nucleic acid array, comprising, in order, the steps of amplifying in situ nucleic acid molecules of a first randomly-patterned, immobilized nucleic acid array comprising a heterogeneous pool of nucleic acid molecules affixed to a support, transferring at least a subset of the nucleic acid molecules produced by such amplifying to a second support, and affixing the subset so transferred to the second support to form a second randomly-patterned, immobilized nucleic acid array, wherein the nucleic acid molecules of the second array occupy positions that correspond to those of the nucleic acid molecules from which they were amplified on the first array, so that the first array serves as a template to produce a plurality, is disclosed.
21 CFR 582.5065 - Linoleic acid.
Code of Federal Regulations, 2012 CFR
... § 582.5065 Linoleic acid. (a) Product. Linoleic acid prepared from edible fats and oils and free from chick-edema factor. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good...
21 CFR 582.5065 - Linoleic acid.
Code of Federal Regulations, 2013 CFR
... § 582.5065 Linoleic acid. (a) Product. Linoleic acid prepared from edible fats and oils and free from chick-edema factor. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good...
21 CFR 582.5065 - Linoleic acid.
Code of Federal Regulations, 2011 CFR
... § 582.5065 Linoleic acid. (a) Product. Linoleic acid prepared from edible fats and oils and free from chick-edema factor. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good...
21 CFR 582.5065 - Linoleic acid.
Code of Federal Regulations, 2014 CFR
... § 582.5065 Linoleic acid. (a) Product. Linoleic acid prepared from edible fats and oils and free from chick-edema factor. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good...
21 CFR 582.5065 - Linoleic acid.
Code of Federal Regulations, 2010 CFR
... § 582.5065 Linoleic acid. (a) Product. Linoleic acid prepared from edible fats and oils and free from chick-edema factor. (b) Conditions of use. This substance is generally recognized as safe when used in accordance with good...
ChemTeacher Resource: Acid Base Titration
NSDL National Science Digital Library
University of Southern California
Acid-Base titration applet that plots pH changes as student adds acid or base. Gives choice of indicators. Compares plots for titration of traditional solution and a buffered solution. Can alter starting concentrations.
Molecular Structure of Nitric acid (aq)
NSDL National Science Digital Library
Nitric acid was first discovered in 1648 by a German chemist, Johann Rudolf. However, in 1901 Wilhelm Ostwald developed the Ostwald Process, which became the principle way of producing nitric acid. During the Ostwald process, ammonia gas is successively oxidized to nitric oxide and nitrogen dioxide by air or oxygen in the presence of a platinum gauze catalyst. Nitric acid has a characteristic choking odor that is acrid and suffocating. It is a caustic and corrosive liquid which will attack some forms of plastics, rubber and coatings. Nitric acid is not combustible, but it may give off poisionous oxides of nitrogen and acid fumes when heated in fire. Nitric acid is mainly used in the production of fertilizers, explosives, flares and rocket propellants. Nitric acids react with toluene in the presence of sulfuric acid to form trinitrotoluene (TNT).
Acid Precipitation in the Pacific Northwest.
ERIC Educational Resources Information Center
Baldwin, John; Kozak, David
Discusses the causes, sources, and problems associated with acid deposition in the Pacific Northwest. Includes a learning activity about acid rain, "Deadly Skies," which was adapted from the Project WILD Aquatic Supplement. (TW)
Nature in the Classroom: Acid Rain.
ERIC Educational Resources Information Center
Doyle, Charles
As a lesson topic, acid rain is defined, its chemistry given, and its development since the 1950s described. The worldwide effects of acid rain are discussed along with the available technology for controlling the problem. (CM)
Acid Rain: The Silent Environmental Threat.
ERIC Educational Resources Information Center
Zmud, Mia
Describes the silent environmental threat posed by acid rain. Caused mainly by manmade pollutants, acid rain damages water and trees, decreases visibility, corrodes monuments, and threatens public health. The article includes guidelines for action. (SM)
46 CFR 153.1046 - Sulfuric acid.
Code of Federal Regulations, 2010 CFR
...LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Special Cargo Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank heating...
46 CFR 153.1046 - Sulfuric acid.
Code of Federal Regulations, 2011 CFR
...LIQUEFIED GAS, OR COMPRESSED GAS HAZARDOUS MATERIALS Operations Special Cargo Procedures § 153.1046 Sulfuric acid. No person may liquefy frozen or congealed sulfuric acid other than by external tank heating...